It’s hit 20s around here in SC.
I’ve spun up my cold natured Willys jeep a few times. Typically, it runs about 30 minutes.
I’m surprised my commie jerk neighbor hasn’t been at the property line staring funny. He’d get ignored.
When I lived in Montana, we and everyone else left unlocked cars and trucks running in the grocery store parking lot while shopping. Every truck and some cars had rifles in them. No problems ever.