Not a good idea. A Wally road bike is going to be a piece of garbage compared to a $50 a day rental road bike. If you want to enjoy riding during your vacation do not consider it. Instead bite the bullet and just rent a nice rental bike. A decent hybrid could likely be rented for half the price of a road bike and would still be more enjoyable to ride compared to a Wally road bike. Also if you have a problem a rental bike will be repaired while a Wally bike will simply be replaced by another piece of garage.