Put up as many as you want - you are not driving further than half of your factory capacity allows. And it will deteriorate in time. As much as I can't refine oil at home, you cannot make replacements for your EV infra. Solar or diesel/oil stockpile, 5-10 years max I'd say.

What would work long term are horses. Nobody can maintain cars if industry and modern manufacturing is no more.

EVs are great toys for the hood, but if shit hits the fan you are not overloading it with your family and stuff, and escaping anywhere.