I'll be honest, I don't have a van...I have a camper trailer and most often are camping in remote areas with no power. I have 120amp hours on board though, and a solar panel, but not enough to be running heaters. We always have a camp fire though, and if it's a super-cold night my wife has a hot water bottle, or outs her cold feet on me to war up. Lol. Not as good as a heater I guess, but something at least.

In Australia cooling is more of an issue I guess.

Good post mate, again..