Go look at them at home cheapo. I've seen them run from $40 to $100 which is a cheap investment. You can get a combo humidistat & thermostat on the better ones. You can add a timer also.
I suggest having a HVAC professional advise on what to do for sure but this isn't a whole lot of money along with a hole in the ceiling and some wiring and insulation issues to deal with. Get a quiet one cause some can be quite noisy when you are trying to sleep.