I apologize if this has already been covered (i did search). We will check out first thing in the morning to head home our last day. Will they let us drop the last day off the DDP? Not sure if it matters, but we are DVC members staying at VWL.
Your dining plan cover the total number of nights on your stay. There is no dropping of them. Knowing that you are checking out that morning, just use them up prior to that, or leave one CS or snack to get something to take with you.
Use the 'extra day' credits to try a Signature restaurant, and grab some portable sandwiches and snacks before you head out to the airport on your last day (assuming, of course, that "first thing" doesn't mean "before anything opens")