Wishfull thinking really.
I am thinking of putting a greenhouse heater in the back of my van, setting it to just above frost and insulating the wire back to the socket in my garage. That will at least keep everything in the van from freezing, but, to be honest it rarely gets that cold these days, even though people think it is cold here in the East, it isn't. Most of the weather comes from the west.
Mind you if it does ever come from the Northeast in the winter we are indeed freeeeezing here!