Not sure about exact temps right now as I am not home, but it's usually 78 to 81. Not sure how to explain how big he is, but he's around 3.5 feet long and almost as thick as a pop can, but not quite. His hides are not tight like a turtle shell because I can see he has some room (especially above him), but he bulges his body thru the opening of his hut? He eats small/medium rats every week and a half or so.
are those temps consistent throughout the cage, or do you have a warm side as well. they need a temperature gradient, and the range you provided would be ok for the cooler side. warm side temps should be between 86-90(ish)