Re: large group suggestions?
Desert party for Illuminations or Fantasmic might work. I have seen them, but never coordinated one. I know the ladies at MEI Mousefan Travel have set up several of them. Might want to give them a call.
Re: large group suggestions?
A backstage tour might be an idea as well.
Re: large group suggestions?
Tomorrowland Terrace Fireworks Dessert Party is another option but is a general booking thing and only holds 50 people. You may want to contact Disney dining and see what the procedure is for a large group, (407) WDW-DINE (939-3463).
ADRs will be tough but some of the dinner shows may be another option ince they can block a large group. Just remember in your planning to let families enjoy themselves. Plus all the Grandma and Grandpas would love quality time with the grandkids allowing many couple to enjoy quality time together for some tours and even a his and her massage.
have a great trip!