I worked in a tire shop/light repairs place in the early 70s. The days before fuel injection when an automatic choke carbureted V8 was the norm. Some of the vehicles started hard and it gets cold in NE MT sometimes. It was quite common to install two freeze plug heaters (one on each bank of a V8) in outfits that had to go each day. 1,000 to 1,250 Watt heaters were the norm. It took a good 20 Amp dedicated circuit for those. 
You are correct that an EV will take more. A 120V charging setup is going to use nearly all the juice getting the battery up to temp to take a charge without damaging the pack in really cold temps. There will be precious little to add charge to the battery if you are just using 110V. A 30 Amp, 240V circuit will add some range at a cost of about a buck an hour if your electricity cost is 15 cents / Kwh. 
Again, I realize I'm just one EV owner but I'd gladly pay double if I was able to charge my car while sleeping at the motel.
I'm booked to spend a night at a Motel in Parachute, CO soon. Room price is reasonable but they are going to charge $12 / night parking fee. Seems a bit steep to me, but I'm not fueling a 1 ton dualey, dragging a fiver down the road either, so it's kind of a bargain by those metrics.