We've been in 20* weather in our Class C, unteathered. And last Saturday, it dipped to 35* at 10,000'. Both our old 2008 Atwood furnace and the new one on the Jayco made it thru the night.
Battery was low the next morning but not dead.
I could see using my Lil' Buddy heater to warm things up a bit. But then, as mentioned I wouldn't leave it on overnight.
I'd set the furnace at 65* or 62* and just blanket up.
A few weeks ago, it dropped to 30*F at elevation and I had forgotten to flip the thermostat to heat. Woke up to a 58* inside temp in the camper.
Now that made getting out of bed difficult. :)
