I am not sure how exact you need to be, but my guess is the the hall is close to 5 feet wide. The door to the bedroom seems to be a standard 4 foot door, and the opening has side panels for the door to close off the room. It's plenty wide for a wheelchair or
scooter, if that is your concern.
I found a 7 minute long video someone took of a Fort Wilderness cabin on Youtube. There is a shot of the hall at right about the 4 minute mark (the videographer was thorough):
http://www.youtube.com/watch?v=XezXUImhJoU
When I watched this video, the cabin looked and its contents looked narrower than in real life, but it gives you a very good overview of what a cabin looks like.
I hope that helps.
TCD