One Idea for heating the Model S in cold climate would be the use of a micro range extender. While providing heat to the cabin, it can produce enough electric power to extend the range to reach the destination or at least the next charging station.
Bladon provides a micro range extender with 6kW electric power but only 15kg in weight.
View attachment Bladon Technology.2.pdf
Bladon provides a micro range extender with 6kW electric power but only 15kg in weight.
View attachment Bladon Technology.2.pdf