I am not an expert. We always stay on site. The ADR window is back to 180 days again. By staying on-site, we can make all our ADR's on the first day, so we get a little head start on others for the days towards the end of our trip. Off-site you can make ADR's, you just don't get this "head start." This may be important when trying to land hard to get ADR's like CRT. If you have a breakfast ADR before park opening, they let you in early. You have to go to the CM. You are supposed to give your ADR number (all we have been asked is to give our name and ADR time, though). Also, if you are staying off-site you can enjoy a meal at one of the resorts. It might be fun to check out a Disney Resort.
Never done CRT (but I have a ds). Paying that kind of money (or using 2 TS) doesn't make sense to me not having a dd! I did consider it once with friends who have a dd, but opted out. As I recall a credit card was needed for the ADR.
We have done Crystal Palace breakfast before Park Opening and after. We prefer before! This is with Pooh and friends.
Liberty Tree Tavern no longer has characters unless you are going during Crystal Palaces rehab.
Friends with a dd did the Princess breakfast in Norway in Epcot and absolutely loved it!!!
Epcot also has Chip and Dale (dinner) at Garden Grill.
DHS has the Playhouse Disney Characters from JoJo's Circus....not really familiar with that one. This is at Hollywood and Vine for breakfast and lunch.
AK has Tusker House Breakfast with Safari Donald and friends. I preferred Donald when he was at Restaurantasaurus... just because we loved Tusker House as a CS!! We have been meaning to put that behind us and give it a try, it gets good reviews.
Cape May Cafe at the Beach Club has a breakfast buffet with Goofy, Minnie and Donald.
Chef Mickey's at the Contemporary is a tradition for us. They have Mickey and friends. This is Breakfast and Dinner.... but during busy times of year they add a lunch. We have never done the lunch, but one year we had a ressie for it and were able to switch that to dinner at the last minute!
Another good one for girls (from what I hear) is 1900 Park Fare at the Grand Floridian. There is the Supercalifragilistic Breakfast with a variety of characters. Lately, Mary Poppins, Alice in Wonderland, and the Mad Hatter.
Dinner is the Cinderella's Gala Feast - Cinderella and Prince Charming,Lady Tremaine, Anastasia, Drizella, and the Fairy Godmother. This may be a good alternative to CRT. We have seen the families coming and going from here and the little girls seem very pleased!!!
Lilo and Stitch's Best Friends Breakfast at O'hana at the Polynesian is another favorite of DS's. Lilo, Stitich, Pluto, and Mickey. Are there. It is the best boy's character buffet.... but I love it too (and I'm a girl!!)
There is also a character meal at the Swan and Dolphin, but I really don't know a thing about that one.
I hope you and your granddaughters have a wonderful trip!!!!