I keep my humidity around 60%, and have never had shed issues at that humidity. If it gets drier (50%), I'll add some sphagnum moss to a hide for shedding purposes.
If your house gets really cold, the double UTH could help to keep the glass from getting too cold. I actually have two UTH's in both of my tanks, on separate thermostats and temp gauges. Yes, it's a little overkill, but the benefit is that if one side ever fails, they at least have somewhere to go. My snakes seem happy and healthy, so it must sort of be working![]()