I don't pay too much attention to my ambients as long as they don't fall into the 70's. Keeping an 86 degree ambient temp is difficult, even in a racking system. As long as it's around 80 degrees you're fine.
As long as your animal is eating well and thermoregulating I wouldn't worry. Whether they are happier in a tank or a bin... my honest opinion. I don't think they give a scaly little squirt, as long as their needs are met. I know the pro's and cons of both, but ultimately it doesn't matter as long as they're healthy.
Switching their enclosures will stress them out temporarily, but so will changing their substrate LOL. They'll acclimate and be fine within a couple of days.