> there’s no reason that these limitations are inherent to a vehicle of this size.

Of course not, but the manufacturer tried to keep the costs down as much as they could. An Ami with A/C for double the price would be a lot less attractive.

Although maybe a reversible heat pump could make the heating kinder on the battery...

> I imagine an Ami-sized car with creature comforts of a regular vehicle would sell extremely well in cities.

Seems rather doubtful, it would still have to provide limited amenities, but the price would shoot way up. And given the range of the car, the amenities are a lot less problematic: you can not use the car for long.