I have a 55 gal with no problems.
It has a large UTH under the warm side set up to a Ranco thermostat and a CHE on each end.
I don't do anything and it maintains a consistent 80 degrees ambient, 91 degree belly temp (checked regularly with infra-red temp gun) and 45% humidity.
I bought a submersible pump and mister nozzles that I was going to set up to a timer to mist once a day for a minute, but I haven't had to.

I agree that in the wild, they have a much larger area to roam.
As long as they have plenty of areas to hide at different temps, I don't see the problem.

He has been shedding in one piece and eats like a champ.

Here's my set up that I built around a glass tank.

http://www.ball-pythons.net/gallery/...016_resize.jpg


http://www.ball-pythons.net/gallery/...015_resize.jpg