I live in ND and travel very rural roads in -30. If I had soup,water, or stew in my pickup, it would be hard as a rock in October and not thaw until May. I can see tow rope, booster cables, a blanket,cell phone charger and keep your gas tank over half full as being useful. Water, lighter, candle, granola bars, whistle, and anything else pretty much useless. Not sure about the batteries on an electric car in -30.. id probably be pulling a gas generator on a trailer. Lol