When I lived in the north it would get COLD. -55C cold. I modded my little 76 Civic's battery pan to accept a battery out of a bulldozer, then on top of the standard block heater I added an inline coolant heater and a battery blanket. I had the luxurious in-car electric heater as well just to help warm the cabin a bit prior to driving away. I had to use extension cords from three different circuits to run it all.