I think EV charging will have to be somehow regulated, e.g., charge only at night, when at home, at a charging station otherwise (which one presumes would have the capacity, though presumes is the operative term). I read one piece that said the increment will be less than that provided by central air taking over. I don't know if that is accurate of course, but it's a thought. Of course, back then we burned a lot of coal.
And it's going to be a while before EVs reach the point of being a major load on the System, outside perhaps CA, and Europe. Denmark seems to be managing "OK", I'm of course ignorant of their actual power situation beyond knowing they buy power from other countries often as not. They had a fair number of wind turbines out in the sea.
Our building has a backup Diesel generator that powers the elevators and emergency lights etc., but not the units. They run it every month or so when not needed I gather to keep it lubed or operative, whatever. It makes some noise. And it's a sizeable unit, probably 4'x10'x6' or so.