this works at 3-4C, falling down the efficiency drops off rapidly.
House geothermic heating is very similar, except the collector is buried under the ground where the temperature doesn't really go negative C (until -30C and depends on the soil, etc). Overall for EV cars in cold winters producing heat is a non-trivial task.
IC engines drive all associated 'accessories' via belts where EV has to have dedicated battery draining motors for everything from windscreen wipers to hvac
That's not completely true. For fuel efficiency, most modern ICE cars drive all the accessories with electric motors, with only the AC and brake booster being powered by the ICE in some cases.
