Rental cars actually add an interesting aspect to all of this: if you use a disposable (not also used to buy your ski pass) email address and the license plate of your rental car for a reservation, the resort will have no way to penalize you for being a no-show! Any attempt at collecting a fine, prohibiting future business, etc. would be against a useless email address and plate number that you don't reuse the next time you visit.
Also, once you've managed to get a reservation, the system allows you to modify the plate number on your reservation, presumably to allow for renting after reserving.