I would eat at EPCOT and enjoy the Illuminations Fireworks show there.
There is a new restaurant in Mexico that is along the water and made for viewing the show if you want to schedule your meal then.
It has an inside restaurant that is One Table service credit
and and outside section that is a counter service credit.
We ate at the outside counter service a few weeks ago and it was very nice. I'm sure the inside one is lovely too.
This is also a nice place to sit for the fireworks show even if you don't eat here...just grab a drink or something and get a seat early.
So many choices in EPCOT at the countries and you will have had a long day with lots of walking there.
It will take you over an hour to get to Cali Grill from EPCOT. With little ones, I wouldn't run to Cali Grill at night (despite a view of the MK fireworks, it is my least favorite signature restaurant).
Just some other choices in EPCOT (all 1 dining credit) are
Norway Princess Dinner (photo included)
Germany Biergarten Buffet with Umpapa band and a place for the kids to dance around.
Morocco-Restaurant Marakesh..with belly dancer
Italy-Via Napoli new pizza restaurant
Land Pavilion Garden Grill-all you can eat served family style restaurant revolves slowly and shows part of the inside of the garden boat ride and has characters (usually chip and dale).
Living Seas Pavilion-Coral Reef with the big tanks of fish swimming by. But i hear only the steaks are good here.
whatever you chose, i'm sure you will have an excellent time!