I live in central Canada, and temperatures reach as low as -30C. Just this week, it’ll be -20C overnight and I always park my car outside. From what people have told me I should idle for 10 minutes when it’s extremely cold, and then drive off. What should I really be doing?
You should not idle to warm up a modern vehicle. Start it. Clean your windows. Set your tunes and then drive with a light foot for a few miles. That will warm up the oil much faster than idling. See this article for the latest advice
If someone’s breath is fogging up and forming a layer of frost on the interior of the windows and they can’t see, best to let it warm a little. Idling may not be best for the engine but dying in a wreck because you can’t see out your windshield is worse.
Turn the AC on but with the temp up or crack a window, it’ll help keep your breath from fogging up the windshield.