Walker Mobility advertise that their scooters are water resistant. There is also an attachment called a charging harness that can be rented with the
scooter to charge the batteries without the whole scooter being taken into the room. We leave our scooter in the car and take only the batteries into the room.
ITA - We always rent from Walker. They have extended range (meaning they go longer without charging) heavy duty (for the Pooh sized) that break down and fit nicely in the car. We almost always stay off site and get a charging harness. The one tip I can give you if you do this - ask for a room near the elevator or wherever the luggage carts are stored.
Why?
Because the batteries are heavy (especially in the extended range/heavy duty scooters). What we do is when we park, I hop out of the car and go get a luggage cart. We then load the batteries on the cart and wheel it to the room (and of course immediately return the cart to be polite)
The other tip I would tell you - make sure you have an extra poncho. While the "Shower cap" may protect the tiller, you will most likely have stuff in the basket of the scooter. (DH tends to be our sherpa on vacation. He rides his trusty steed and carries my packages and sometimes my purse). If it does start raining, you can cover your precious stuff that's in the basket with the extra poncho.