Do make sure your tailpipe is clear and not filling your garage. Our family once used a propane grill as heating source (the food was a nice plus). I have one

Do make sure your tailpipe is clear and not filling your garage. Our family once used a propane grill as heating source (the food was a nice plus). I have one friend with a ICE vehicle that he can plug into the house and power some essentials. He is a general contractor and has a lot of fun stuff on his truck. How well do EVs function as emergency shelter? I would be curious on a statement from each manufacture on how long I could run the heater in an emergency situation.