If you aren't having good luck scheduling Garden Grocer or wegoshop for your arrival date, the only other alternatives I can think of are to either take a taxi to a grocery or try the Hess Convenience Store at DTD. If you decide to take the taxi, take Disney transport to DTD and taxi from there to Winn Dixie or Walgreens on SR535 (it will be about two miles or so from the Marketplace end of DTD) to save some money. The Hess store is across the street from DTD - close to the entrance by World of Disney. Personally, I would do the taxi, because I wouldn't want to carry that much weight around.