Keep checking. People do cancel all the time - particularly the night before. Search for "off" times and search for specific times vs. the generic meal (e.g. "lunch"). If your party is an odd number, +1 and search for an even number (e.g. if you're a party of 3, search for 4). Consider one of the reservation finder services. Touring Plans has the only one I'm familiar with. It's free but you do have to register for a free account. It will search for reservations within your specifications and notify you when one comes available ... but it's up to you to react quickly and log into the Disney site and book for yourself. Good luck!