“involuntarily volunteered” Lol! You mean “drafted”.
If you’re going to head off this impending disaster, start now by insisting that you can’t do all the cooking- surely that is obvious, or ought to be. Make it real for them by sending out an email with a signup sheet to cook, with the aforementioned list of dietary needs attached. Figure out who the drivers will be and ask them if they are willing to drive the party bus home from bluezoo. They are going to have to be stone cold sober all week.
You’ve got to name names. And then sweetly say, “Or, we could just let Disney take care of all these little details.” That is, after all, what you’re paying Disney for.