I live in MN, so I have the same issue with having a cold house.
I have enclosures that are similar in size to a T8 ,and I have CHE's hooked to a thermostat
that keep the ambient temp where it should be, and flexwatt hooked to another thermostat for
a hot spot. This keeps the temps perfect, but the CHE's kill the humidity. I just put large humid hides
in the enclosure, and large water dishes. They use the humid hides when they need to, and
have had perfect sheds. In the summer, the CHE's don't come on often, so the humidity stays
up better.