In any case, the key point is that in an ICE car the heating is mostly "free" since the engine has perhaps 40% efficiency and the majority of heat released by combustion is unused/unusable waste heat that might as well be used to heat up the car if you need to, but in an EV you don't have that source of free waste heat to tap into, and you have to use the energy that you could have used for moving the car instead.
Some cars do have additional resistive heating or heat pumping through AC, where that is technically driven by engine power, but not from the waste heat.
> Also don't forget that seat heaters are also resistive and most cars in cold climates have them.
I know it (or more like my bum) too damn well, though I didn't think about them in this case.
> small diesels like VW Polo
Makes sense, though as I understood, it's strictly auxiliary till the engine is heated aaaand maybe some additional heating at the parking lot with the engine turned off, though I would wary of this usage, it would drain even the extended battery fast.
Overall it's not quite what I had in my mind (think of space heaters), though yes, there are some parts which can operate independently from the engine, though it's not a primary function for them.