I said it once, twice, and now three times. Book 180 days out, get the 8am reservation. Enjoy the buffet and be out by 8:45. You will not wait for any thing for longer than 15 mins. Just keep the res. food is decent and you get to see OTHER characters. If your kids want to meet Anna and Elsa I'm sure they want to meet belle and aurora.
Stay calm and happy. Don't pay an extra fee just to dump a reservations so you can be five minutes in front of somebody who ate breakfast. When you sit down at breakfast just ask for your check right off the bats you can pay it and be done. So, when your done eating, you can just leave.