When our sully was not quite 3 months old. We left our home hastily to get away from a hurricane coming our way. I put a large box together with Opo's substrate, hide and water dish. I forget his UVB and heat supply. We couldn't stand our hotel room being 80 or 85 degrees. So the first night Opo slept on my chest, covered with the blanket. Needless to say I didn't get a good night's sleep, but Opo slept like a log.
Nowadays, if the room is 70-74deg, his covered doggie bed with an extra thin blanket over it keeps the carapace 84-88deg with no light/heat so 18 hours of the day there is no extra power required summer or winter. Only lights for morning warm up if it is not sunny outside.