> Also think about when peak demand happens -- late afternoon on hot summer days. Right at the time when people are getting home, with their EVs discharged (or at least, not at full capacity) after a day's use.

Not completely discharged - the little available per car will add up to a lot when there are a lot of EVs. The EV owners who decide to sell to the grid at peak hours (at higher prices) might make a profit doing so.