I use the Vision racks and i keep them in my basement. Its a finished basement and well insulated. I keep the room at 78 degrees with an oil filled radiant space heater. The vision racks dont come with the best heating cord or enough to propperly heat each tub. I bought 2 of the longest heat ropes that big apple sells. Now each tub has 1/4 of the bottom covered and it works perfectly.
To keep the humidity higher then normal i have a huge tub filled with water and a small fountain in my basement.