Everyone seems to have a room assignment sheet. The security guards that clear you onto the property, the porters and the folks in the terminal. The porters have a pocket full of blank luggage tags. Last one we dealt with (Disney) handed me a sharpie to change the room number on my tags. It all works out. They've done it before.
Only bad moment was that I was convinced I had been DOWN graded until I got inside and looked at the deck plan. They said they have to put up with that a lot.