M.,
While I don't quite understand how your son walked the halls last time you were in a hotel, I have a few words of advice. First, when you get to the hotel make sure you are on the ground If you make sure they know the ages of your kids and that they may be active they can try to put you at a less occupied floor or section of the hotel so you won't disturb or be disturbed by other guests! Next, make sure you use the door lock that most hotels have on their doors, not just the deadbolt, as most of them disengage when you pull the handle, use the thing that is like a chain on a regular door, it is higher, out of reach of little hands, and keeps the door from opening all the way, decreasing the chance to "escape" for your little one. Third, bring some familiar bed linens, like pillow, blanket, and so on. The smell and familiarity will be a comfort to him at bed time. My youngest hates any break in his routine, if yours is the same he'll need to have things close to him that he knows. Depending on your length of stay, he should be ok after the first or second nights there, it is an adjustment. Beyond that, I'd say be prepared to be up the first night to comfort him and let him know it is all okay!
Good luck.