january of 2011 we had some really below 0 weather in minneapolis.
just to see what it would take to stay warm with a stove kit in the older car i used for general running around I did some testing.
our SUV was much more reliable and I never went anywhere I could not call a tow on my flip phone,no iPhone then.
the end result was that even at 15/20 below I could warm the car up without running the heater and using up gas.one thing I did not do was run the stove until the propane ran out to see how long it lasted.i did keep a sleeping bag and blanket in the car.
if I did any "up north" driving to winter camp I would have a full
set of winter gear along anyway.
I was going to send a photo but I don't see how to do that now.
most photo down loads let you click select on the shot.
nothing to see really just a big coleman burner on a propane bottle on the floor with a thermometer and stuff on the seat.
I would skip the campfire and have a stove of some sort along.