Hi, Amy!
I'm loving your way of thinking, especially since I too am always looking for any chance to extend my vacations to the Walt Disney World Resort!
The rules state that Guests staying at Disney-owned Resorts are able to make their Advanced Dining Reservations for their entire trip [up to 10 days] on the first day of their 180-day window. So, you would only be able to make your dining reservations 180 days out for that first reservation and starting the next day, you'd be able able to make them for the rest of your trip. The reason for that is because they are on separate reservations. If you just added a day to the beginning of your existing Resort reservation, you'd be able to make them on that first day. I hope that makes sense!
Something I'd also like to point out is that you can make your Advanced Dining Reservations
online starting at 6:00 a.m. Eastern or you can call Disney Dining at 407.WDW.DINE [939.3463] starting at 7:00 a.m. Eastern seven days a week!
Thanks for stopping by the Moms Panel, Amy! Please don't hesitate to write back if you have any other questions we can help with!
Wishing you Pixie Dusted vacation planning!
~Jackie