An alternative that a lot of people do is rent a car just for holiday, as it ends up cheaper. Or just get the train and rent on arrival.
But there are just no EV to rent anywhere in France. The ones you you find on Getaround, Ouicar or other peer to peer renting sites cannot actually be rented (owners always reject the inquiry upon request -- probably a trick by the website operator to get people to at least request some cars and get an ICE anyway).
Note that I only checked for big renting companies (Sixt, Enterprise, ...). I was very surprised!