Dickinson Marine heater

Thinking out of the box a bit. I had some one come to me with a similar problem, sking and ice fishing with a camper,(think it was a wolfcreek 850) trying to keep it warm etc. We did some experiments to see if we could offset the power usage of the forced air furnace with solar. Doesn't sound like much of a challenge but with short winter days and not always sunny conditions it was surprising. After all was said and done it looked like it would need a solid 250 watts of solar to make it happen. I laid out the option for him and he had to decide between that and going with a Plat Cat furnace which presented its own challenges for install. He opted for the solar for a couple reasons. He never used his canoe rack in the winter and worse case scenario if it didn't work out for him he would have a killer solar system. We managed to squeeze a 160 and a 140 watt solar panel on the roof and he hasn't looked back since. In good sunny conditions its way overkill but in bad conditions it seems to work out for him and he has had no problem with one week dry camping stays. He says he tends to park in spots where the sun can hit the roof a little easier but other than that it seems to have worked out for him. He also got rid of all his incandescent lamps and changed them with LED's which I think made a significant difference.

Not sure if it would work for you but something to think about. Seems to me he spent about 900 bucks or so.