Thanks for the advice. I think that the Rose & Crown is a great idea!I am sorry Remy is no longer there for your son to enjoy. We got to see him a few times and it really was fun for the kids. The food at Chefs is good and we had been there before Remy appeared but must admit that was mostly the reason we had returned lately. We've also had lunch there, I enjoyed it as well if you find that menu more appealing.
Other nearby "fun" ideas for your son might include reserving a table at Rose & Crown late enough to request a table outside and then stay there to watch Illuminations. It is a great close up view that our kids enjoy.
Also Teppan Edo is another they've enjoyed. They like watching the chef prepare the meal and some of the kids meals were served in a monorail-style plate. They're older now so not sure they serve them that way anymore.
Rose & Crown is just inside International Gateway, closer than France even, and Teppan Edo is a bit further than Chefs but not a long walk.
I also second the PP who suggested no earlier than 6 pm if you want to enjoy the CL offerings. Sometimes it might not open right at 5 pm, there will be others in line, time to enjoy the food/drinks, make your way down from the 5th floor, walk over to International Gateway, go through bag check and scan bands for entrance, walk to restaurant. Not trying to make it sound like that takes a lot of time, but don't want you to feel rushed and watching the clock when you eat/drink.
Hope you enjoy your stay at BC!