I actually keep a rack in a room that averages 66ºF. It can be done but is not easy. Mine is a 5 hole rack I have flexwatt 11inch for the hot side and 17inch for the cool sides I run the top 3 slots hot side on one probe the bottom 2 slots hot side on a second the top 4 cool sides on a third and the bottom cool side on a fourth... The floor is cold. The rack is well insulated top bottom and sides.

I had also to balance the way air moves in and through each tub and shelf. It is many times easier to heat the room. I would if it was reasonable. There is a reason why most that use snake racks have snake rooms to match.