In my experience, it's all cars in Canada- I've never seen one that doesn't have it (other than imports). I guess you could probably get away without it on the west coast.
Most cars do start though. It’s really a maintenance issue, where it’s bad for your car to start it at -30 (as the linked article says). In my experience, a newer car in decent shape will start consistently.
You'd have a very hard time starting a diesel without a block heater. When I lived in Canada I kept an older Ford (a 1949 one!) around for winter use because the diesel tractor was that much harder to start. You can make things a bit better by mixing about 5% gasoline in with the diesel to avoid the diesel becoming flaky but that has limits too and the Canadian winters can throw -40 Celsius at you with some regularity.
Yeah my E39 doesn't have any sort of heater and it came from BC. I've not seen anywhere to plug a block heater in though BMW did sell auxiliary coolant heaters (from Webasto). Of course if I lived in a climate where block heaters were required a BMW wouldn't be my first choice. The heated seats and steering wheel come in handy more than I thought they would tho.
-Block heaters are quite common in Norway, too - and while my old diesel will start in -30C without one, it does not like it. (I cheat, though - the starter motor is pilfered from a light truck, and two batteries with approx. 800 CCA each work in parallel to make it turn over; it was a necessity as there is no electricity where we park the car before heading for our cabin in the mountains...)
In addition to less engine wear, it also works wonders for fuel consumption and makes the car comfortably warm in a couple of minutes.
Based on your name, I suggest coming west, but not too far west :). Trying to start a car at -40 in SK is rough... if you've got a good battery and thin oil you might be able to, but it's so much nicer after the block heater's been going for a few hours.
Gasoline powered cars in good repair will start just fine any any temperature the North American continent can provide. Block heaters are to speed warmup and reduce wear.
Most cars do start though. It’s really a maintenance issue, where it’s bad for your car to start it at -30 (as the linked article says). In my experience, a newer car in decent shape will start consistently.