Hi Gay,
I'm so pleased you like the Moms Panel I hope you've gained some hints and tips from us to make your trip magical!
I would definitely keep trying to get the dining reservations you require, as you say cancellations happen all the time. What I also suggest you do is have a look online, if you go to your required restaurant on
www.disneyworld.com you'll see a button to push to book. Here you can check availability at all of the Disney restaurants and book what you want. Try different times as sometimes it will say no availability but if you try for 30 minutes later it finds an opening also try unusual times.
If you're unable to get reservations you can try walking up but from previous experience I've seen most people turned away at the podium when they try. Your best bet is to try and get reservations even if they're not for your first choice.
It sounds as though you have definitely decided where you'd to dine but some of my families favourite restaurants aren't the most popular ones. For example we love Kona Cafe and 'Ohanas at the Polynesian and if you like spicy food then Boma at Animal Kingdom Lodge is a great choice.
I hope you get something and have a great trip,
Jo