I'm sorry you didn't have time to put a picnic together at the only entertainment venue where you don't get frisked.
Saturday night, (Folds/Wainwright) we had a wheeled cart with a picnic basket and cooler with cheese, salami, wine, cola, and a spinach salad with bacon, blue cheese, grape tomatoes, red onion and a quick balsamic vinagrette (salt, pepper, EVOO, balsamic and thyme). All of 15 minutes to prep. Well, desert took longer: the Mrs. made chocolate mousse (the primary reason for the cooler), in ice-cream cone cups coated with more chocolate. Our friends came with their own picnic basket; more wine, cheese, crackers and breads, and sliced flank steak from Whole Foods, and some other desert items left over from a recent party.
Originally, we'd planned to make fondue, but they've banned all fuels or charcoal. Possibly we could have gotten away with sterno or tea-light-based heat, but only if we'd pre-melted the cheese and just re-warmed it there.