Hi Carol!
As a "Nana" myself this warms my heart! Since I am not sure what types of things you may have done, I will suggest a variety, and hopefully, that will get your creative juices flowing.
Since IllumiNations: Reflections of Earth is ending soon, I would recommend considering a specialty cruise to view the show. You can enjoy a short cruise around Crescent Lake with snacks and soft drinks provided. Then, you will dock with a clear, uncrowded view of the spectacular.
Another idea is to have a special dinner at a Signature Table Service location. In my experience, as kids grow older, they appreciate this type of dining differently. If you have not experienced the
California Grill followed by Happily Ever After fireworks from the top of Disney's Contemporary Resort, now might be the time!
For something extraordinary, I highly recommend the
Backstage Magic tour. I had the pleasure of experiencing this tour recently, and it was amazing! At your grandchildren's ages, just enough magic is revealed to truly enhance their experience of the Parks.
A laid back option would be a day at Disney's Fort Wilderness Resort. You could start by renting a golf cart to zip around in. Your options could include kayaking, bicycle riding, touring the
Triple-Circle-D Ranch and enjoying a trail ride on one of Disney's trusty steads, along with archery and many other fun adventures. You could then have dinner at Trail's End and top off your day at Chip 'n' Dale's Campfire Sing-a-long with s'mores, cowboy songs, and dancing with my two favorite chipmunks!
I hope these ideas help!
See ya real soon,
Anne