Hi Lacey,
This must be an exciting time for your kids as they anticipate their first trip to Walt Disney World. My children always enjoy counting down to the trip and the closer it gets, the more animated they become with their excitement.
Unfortunately, many table service restaurants book up as early as 180 days out, and with Thanksgiving being a very popular time to visit, this is probably the case. I definitely suggest you keep trying, especially if there is a location you really want to try. You never know when there might be a cancellation. However, this is never a guarantee.
In regards to the Disney Dining Plans, you could still consider the
Quick Service Dining Plan. This plan offers (2) Quick-service meals and (1) snack per person, per night of your package stay. Quick-service locations do not require reservations, so you would still be able to get the value and convenience of a dining plan without having to worry about securing reservations.
I hope this helps. Have a magical trip filled with treasured memories that last a lifetime.
~Allison L