Oh yeah, about "worst case emergency" (the one that might require use of the tow vehicle battery). I wonder what that can be. No, really.
To me, such an emergency would be 3-weeks food supply in fridge with frozen meat etc going rotten. But they only have a small fridge (2 cu.ft?), so part of their supply is already canned and dry goods. No emergency here.
Furnace? In a wilderness you can't rely on it 100%, a good duvet or 30F sleeping bag is a must to have, as a backup.
Lights? Since when lights (other than for truck repair) are an emergency, to begin with. There is a simple and cheap emergency light for trailer, I learned this from kayaking buddies - lawn LED light:
Cut the stake off, tie a string around the top and hang it on the South side of the trailer. When night comes, hang it on the kitchen cabinet door knob or wherever, it will provide a usable light for 5-6 hours. Cost me $1 in local supermarket. I stopped using my flashlight on the camp since got this thing.
