Don’t know about the heater aspect since I live in the SF Bay Area. I use a small electric heater where I stand since we don’t get truly cold weather here.
But when we do get colder nights in Jan/Feb (and cold of us is about 36-40 degrees) I keep 2 reptile tank heat mats inside my GF. I have them on a timer that comes on about 9pm and turns off about 7am. And I keep the unit covered with a heavy blanket. I’ve seen comments that others use a heating blanket to keep the unit warm when not in use. Another factor in the temp issue to consider.