When did I say organized? And evacuations can happen before and after an emergency. Evacuating just means leaving the unsafe place for a safe space, it doesn't define the order of things. I've evacuated before and after major storms depending on the circumstances at the time.
Leaving a burning building is still evacuating the burning building. Evacuating a burning building doesn't mean it's an orderly thing before the fire starts.
If you're part of an organized evacuation, you're doing this before the storm -- correct?
And if that's the case, then: It doesn't matter how long an EV will or will not run the stuff inside of your home, because you won't be there.