If your BP is hanging out on the cool side then thats where it wants to be. When it needs to thermoregulate it will, BPs really don't have a favorite hide, they go where they want to go to thermoregulate.
As far as room temp goes, I think it's easier to keep the room warm with a space heater. A radiant heater attached to a Ranco works great. And if you have one snake you will eventually have more, just seems to work that way. Good link with everything.