You probably don't want to do that with a gasoline engine. The places I go in Quebec, businesses and parking lots have electric outlets at each parking spot where people plug in crankcase heaters. Most cars you see have a short electrical cord hanging out of their grill. Cold antifreeze isn't a problem, but motor oil gets very thick and makes it hard to crank (or lubricate) a cold engine, though I've never had a problem with rental cars.
My first winter in QC, I got one of those heaters installed. It started shorting out last year, so is now inoperative. But to give you an idea how cold it gets, the first real cold snap, I slid on some ice, and rear ended a mini van. Took out my radiator, causing all my coolant to drain onto the road. There was a radiator shop just a few doors down from my girlfriend's house, which was about six miles from where I had the accident. I took the chance, and drove the six miles with no coolant in my Durango (318ci). The engine was just starting to warm up as I pulled into the radiator shop.
So I had warmed up the car for fifteen minutes before I left the house, drove six miles, got in an accident, spent about fifteen minutes talking to the lady I hit, and then drove six more miles, all on whatever coolant was trapped in the engine block by the thermostat.
There's a special kind of cold that seems to swirl in that vortex that meanders between Montreal and Quebec City.
