As someone who had an 80's diesel car as his first, I can verify that even leaving them in a high school parking lot during a cold winter school day in Maine is

As someone who had an 80's diesel car as his first, I can verify that even leaving them in a high school parking lot during a cold winter school day in Maine is a bad idea. I had to wait about a week for the weather to warm up before the glow-plugs were enough to start it. However, I believe a Tesla is a different case. I always keep my car's fuel tank above half-filled to preserve the fuel filter (and you should too). While the Tesla might lose some charge during the day in a parking lot or overnight, I can't imagine it would be a seriously substantial amount.