I have to admit - I would be really thrilled to win, too.
I am guessing, like others have stated, that not only will they not allow people to roam freely in the HM (darn it) and the winner will likely have a CM with them, glued to their sides the whole time, but they may even have some sort of hidden room for CMs somewhere in the HM that they can set up as a bedroom. They would have to let the guests be near a bathroom of some kind (don't want to have an accident in the middle of the night in the HM!

), so that makes me think there must be some separate room in the HM building, out of way and off the main track of the actual ride areas. And they probably lock it at night so you can't roam freely anywhere.
Ooooh, it's so exciting! I can't wait to hear more details!