At just above 20 degrees Celsius, the average EV outperformed its stated range, but at minus 15 degrees the average EV had only 54% of its rated range, the study found.

A 2020 study of 4,200 connected EVs of all makes by Canada-based telematics provider Geotab found that most models had a similar drop in range in cold weather, primarily because the battery is also used to heat the car for the driver and passengers.

Hmm. I wonder how hard it would be to improve thermal insulation on the cabin on cars. I mean, double-paned glass and so forth. Thermal insulation in the walls and floors and ceiling. Maybe aerogel or something if one really wants to save on weight.

Insulation means weight. More weight is bad, reduces fuel efficiency, but with EVs, you also get regenerative braking, which avoids some of the cost of weight.

With internal combustion vehicles, you have a bunch of waste heat that you get for free, so at least for heating -- maybe not air conditioning -- there's not much point in worrying too much about thermal efficiency. You have more heat than you know what to do with.

So given the combination of weight being more-expensive on ICE vehicles and heat being just about free, you wouldn't have had a lot of incentive to optimize for that set of tradeoffs; I'd assume under-spending on R&D.

And maybe run the car's ventilation through a counter-flow heat exchanger to recover heat before venting it to the outside.