We have biozones in the house tonight. Greta and Cody like it cold, I like it medium, the little ones like it HOT. Bitty wants to sleep with Dottie (for the warmth) and Prissy is jealous. So finally, I put a blanket in the bathtub and put the three black and white units in there. The bathroom is tiny, has it's own vent, and is the warmest room in the entire house.
This may be a good solution for the entire winter-last year was tough because someone was always uncomfortable.