@Dbend121 the fuel heater isn't designed to run for a longer period of time. If the heater runs continously, you will have a serious risk of fire under the bonet that could seriously harm or even kill you while you're sleeping. The battery would also be drained in no time. So, that's really no good idea. Get yourself a well isolated sleeping bag and leave a window or the sunroof slightly open for ventilation while you sleep, or get a car that is meant to use for sleeping inside, like a camper van or RCV.

Integration in Google Home, Alexa and so on would be great, but I don't think that such feature will be realized in the near future.