Nothing to stop you messaging a bunch of girls on aw and like you say offer "good money" if they work outside their normal hours. Also address the main concern I'd have, namely that you would not be drunk or on something. Again like said check with her whether late night access to the hotel is ok.
Edit: Another thought are the lapdancing clubs. It's not ideal in the slightest trying it in there, but a lot of dancers do escort. Plus they are open very late. Whether they can host is another concern.