They dont need UVB / UVA they get all their vitamins and nutrients from whole prey items.
They can stress as younger animals in too large of an enclosure, but you can put up blinds to make it smaller and expand as needed.
Hibernation is only crucial for breeding - the cooling period has to happen in order for the females to be reproductive.
Feeding frequency and size?? This is not really covered because there is no set rule. Some feed every few days, some feed once a week, some feed once every other week. You can do smaller more frequent meals, or treat them like in the wild and feed larger more spaced out meals. It's not uncommon for Gila to only come out after a rain storm in the wild and then they will feed and consume around 30-50% of their body weight in food before retreating back for another month or 2 before returning to the next rains. They are SLOW metabolizing creatures. Diet can consist of chicks, rats, mice, hamsters, gerbils, raw egg (quail at room temperature preferred and enjoyed full shell).
They do fine kept cooler at night and warmer during the day. Dont expect them to bask much but occasionally. We use a basking spot around 92 under the tank and keep ambient around 75 for the most part. At night things drop a little in ambient to 72 but the basking spot stays on since its an UTH.
Humid hides are welcomed. They spend most of their time underground where the humidity is higher than the dry desert air. I just throw some moss under their hides and mist it once a week or so. But i also give them large water areas and they absolutely LOVE destroying them. More so than my friends...
They are easy. But they are venomous. Don't be stupid. Know your laws. Also buy 2 books:
https://www.amazon.com/Biology-Monst...iology+of+gila
https://www.amazon.com/Beaded-Lizard...QT8XPTFWGEMZWT
Also buy a bite protocol from Joe Pittman via facebook.