Hi mate, You're right to approach the logistics of using hotels to play in with a degree of caution. That said my experience of staying in quite a few (from budget end of market through to some of the very best there are anywhere) over nearly 40 years, for business, holiday and deffinately as a PIG FUCK PIT means developed a few ideas for myself on this. They seem to apply in most situations but they're not cast-iron and I don't now or have ever worked in the hotel industry so I can't claim these come from knowing the business.
First off, yep the "motel" type that are all over USA are best for the reasons you said. The Campanille chain (The Accor Hotels group of France) USED to have a pressence in the UK and their locations were built to that "motel" layout and all rooms with access direct outside at ground and first floor (via an exterior landing with outdoor stairwells). Accor closed down the brand some years ago HOWEVER some of them were bought as going concerns and contined to opperate. I know at least one that operates still today (Now know as "the Blue Hotel" in Redditch. There may be others I'd do some googling etc. as there may be more.
The above said, the fact is mate that virtually EVERY hotel in the UK is much LESS interested what guests get upto than you might imagine in my experience, seriously. (This DOES NOT apply to B+B, where its the managements home as well as business OR perhaps stand-alone single site hotels where again the owner may be running it and therefore its more "personal" and in those places they'll take more notice of whats going on). But in chain hotels in UK no matter if you're at the "premier inn" end or "Mal Maison" etc so long as you remember a few things you'll be fine. (1) you're paying for the ROOM, not per guest so you dont need to sneek people in. (2) Hotels have been around for centuries and as long as they've existed punters have using them to fuck in and sure, the manager at the place you're staying on a given night MAY only look as old as 24 but if they're manager they come from that LONG history. (3) Ditto the more junior staff moreover none of them are paid a fortune and they worked hard for it, meaning many hotel workers dont look to do more work than they have to and I dont blame them. So they're really NOT keen to look too hard at what guests are getting upto, 'cos if they take too much notice they might see something they have to do something about and thats extra work for them. (4) with that idea of "staff work hard enough asnd dont want more" in mind REALLY try and avoid causing excess work for people like house keeping staff who sort your room during / after stay 'cos if you do (for example leave your room a shit tip) and it takes way more effort / time than it should to clean then they are required to report it to head house-keeper ;/ manager and you could find yourself getting a shitty letter / phone call / banned from staying ANYWHERE in that whole hotel chain again and all these could take some explaining in your other, non-pig, life. So keep staff sweet. This erxtends to maybe taking a few play towels (tesco basics range are perfect) / cheep matress protector - a few quid from tesco so you're NOT leaving linens really filthy and cover in gunk like jlube if your doing arse play. When you leave them with you in a bin bag inside your luggage then launder and use again next shag and if that not possible for domestic reasons then DUMP in a bin once you're out of hotel AND DONT FORGET TO DUMP IT before getting home as partner finding bin bag of j-lube covered towels etc in the boot a few days later 'cos you forgot to get rid is likely to be as much of a sign something is going on as them finding an "odd" stain on the car upholstery along with a pair of Calvin Kleins in a size not yours or your partners size in the gove box or your partners size and noticing theirs trainer footprints on the interior roof liming <LOL> its not a story you can make convincing as to why the hotel trash is there so get rid! (5) goes without saying follow the basics in terms of use of your room... Keep noise down, no smoking (including METH clouds - or keep to minimum and exhale into the airvent in the bathroom that starts everytime you turn on the light) **REMEMBER: hotel rooms have VERY SENSITIVE smoke alarms. METH CLOUDS *WILL* ACTIVATE THEM. KEEP THE METH PIPE WELL CLEAR OF THESE**, etc. Don't stand out from other guests and dont disturb other rooms / guests so they complain and someone comes knocking on your door is the principle (6) on the "someone knocking on the door" point previously, if they do and want entry to the room they can. So if you ARE using ANYTHING that could be a problem if you had to let someone from the hotel into your room there and then, at the moment they knock at the door, then GET OUT, USE IT then IMMEDIATELY PUT IT AWAY AGAIN, preferably in a suitable bag / case of your own RATHER THAN use a drawer in the desk or to shelf in a wardrobe. Basically think about stuff left laying around the room and its never a good look to answer the door with someone listening to sound of you and the shag (and someone at the door WILL hear the panic of trying to hide stuff) drawers opening and slamming etc, panic filled conversations in low voices. So keep stuff AWAY once used not out on view ('cos in a panic something is bound to get missed). Just think: does something you're using come under the "embarressing" category OR does it break hotel policy / rules OR does it break the law??? First one in that list, like three monster dildo by ther bed, no an issue, someone blushes. If you get all hot awkward 'cos its been left on show, well suck it up and fucking own it giving the manager in your room a cheeky smile and he'll probably be the one now flustered. If its a hotel policy broken (eg smoking in the room) you'll gert stung with a nasty £250 extra bill or simular for extra room cleaning and MAY be asked to leave there and then so your night of fucking is, well... FUCKED and you're sleeping in your car in the most quiet, out of the way and darkest place you can find.... and sadly the only place you can find that gets (no where) near to those three objectives is an ASDA carpark complete with flood light thats next to the a railway siding and a major motorway interchange thats busy 24/7. Not good but NOT "fatal". Leaving chems parafinalia etc, including used rigs AND ESPECIALLY LEAVING DRUGS OUT where hotel staff might see it, thats the big NO-NO!! Cos they'll almost certainly call plod ('cos they'd be worried that you'll become an issue during your stay that they'll have to handle alone. So getting plod to come take someone in for questioning is fine by the hotel. It's "away"and thats all they care about but not something any guest like you and me mate would want... plod asking questions you REALLY dont want to answer. (7) make use of the "do not disturb" tag for the outside of your bedroom door to stop someone from room service or house-keeping next morning come barging in when you dont need that. House-keeping next day are the worse as they're on a mission to turn room around for next guest and (prior covid) most hotel chains only give one person a MAXIMUM of 20 to 30 mins to completely turn around a room between guests and so the poor buggers who are trying to achieve that have a habit of doing the following simitaniously: knock, say "housekeeeeeping" open the door, and be through it in less than 2 seconds flat and while carrying a pile of bedding, a hoover and tin lemon pledge / duster. But the speed they move is potentially problematic and the "do not disturb" sign rarely is effective SO IF YOUR ROOM HAS CHAIN OR SIMULAR ON DOOR USE IT ALWAYS(!!) when you're in the room.
They're something else but cant think what it is but will msg you once i do. Hope this has been some help and re-assures you that if your sensible hotels, ALL hotels and not just "motels" are viable for meeting up to fuck. Yorki