So I am NE Ohio, and moved into a new house as of this year which has 2 floors. My Cham is upstairs in the bedroom because it’s the least trafficked. It’s starting to get cold at night (40s) but not enough to turn the furnace on and make the downstairs into an oven. I cover the cage right as lights go off. What are my best options? CHE bulb in my dual-fixture on a thermostat? Or actual CHE? Space/oil heater?