I read that the Tesla MY is good for this, including a camping mode designed for it. I suppose an M3 might also work, but would have less room to stretch out?
Are there other EVs that would be good for this, with a heat pump, something that’d serve as a camping mode, and enough space for two people to lie down and sleep with the back seats folded down?
Just get one that has outlets you can use. Set up a tent and power electric blankets inside your sleeping bags. Typical electric blankets run at 50 watts. So overnight at 8 hours of sleep you would only drain the battery by 0.4 kwh per electric blanket at most.