A few thoughts.
We live in Washington and camp year round primarily on the westerm side. If you are dry camping out here in winter I don’t believe you can make a system without a generator work, especially with a compression fridge. It’s just to dark, to cloudy, and too many trees. Our experience in winter is that our solar does little or nothing.
The other thing I would worry about is the temperature limitations for charging the Lithium cells. It can get cold here especially if you have an altitude and, depending on where the batteries are located in the camper and how much heat they get, could be a big problem.
Finally, the Truma systems are pretty neat but they do seem to be slow heating. We tend to sleep with the heat turned way down under a pile of comforters. Besides liking sleeping warm with cold noses it saves a lot of propane and power. It is nice when the furnace kicks in and then heats the camper back up in the morning. The Truma may take a while to do that.
