If you're staying at a WDW owned-and-operated resort, you can get a free ride from Disney's Magical Express and arrange for a grocery delivery. I wish I could arrange a grocery delivery everywhere I vacation ... to me, it's so much nicer and more convenient than trying to find things in a strange store and then waiting in line with a bunch of other tourists.
I live in a touristy resort area (right next door to Atlantic City, NJ), and when people I know are going to be renting a place in the area I always advise them to get a grocery delivery rather than waste some of their vacation time waiting in line at the supermarket, something they do enough of during the other 51 weeks of the year.