We just got information from the CMs at POP, they gave us exact directions. Of course, we'd already checked in. So if you're going to stop on the way, you may want to look up Publix in whitepages.com, find the location closest to WDW (you can aerial map it as well) and then mapquest from MCO to Publix.
Sounds like a lot, but I mapquested most places before we went, and boy did it save on aggravation and lost time. Definitely worth it to plan ahead like this.