Although it might be possible, I would think it would be pretty stressful. Would you be at DHS at day, then go to dinner, and then back for Fantasmic? If so, I just think it might be better to do one of those on a MK day or even an Epcot day (monorail). Instead, why not walk over or take the boat over to one of the Boardwalk restaurants or Cape May at BC. Actually, even a restaurant at the World Showcase would be easier. In September, we are an early dinner at the Garden Grill and then walked over to DHS for Fantasmic. I think our dinner was at 5:30 or 6 and Fantasmic was at 8:30...we literally sat down 5 minutes before the show started!