[rich2468]

It's pretty easy to heat a TrailManor well into the 70 degree range with a single 1500 Watt electric heater (adding a fan or two for air movement) at 30 degrees outside temperature.

If you're staying at a KOA or other campground with electric power at the sites, you're paying for electricity whether you use it or not. I will not argue the safety aspects of a Mr. Heater Buddy, but will say that you're pretty much 100% safe from Carbon Monoxide poisoning when using an electric heater and one will certainly do the job under your use case.

I've camped under colder conditions in a larger TrailManor (2922KB) and only used the furnace when wanting to heat up the camper quickly following setup.