Good idea, then! I can understand - my son has food allergies, and I used to have some soy milk and snacks always in the room for him to have (we also used to have to give him extra soy high calorie mix daily in some soy milk).
Maybe also call the gift shop of your resort - I'm sure if you call the resort they will connect you. Since it's a health issue, maybe they can arrange to have a supply of whole milk for you if they don't normally carry it? Or they may have it? If it were me, though, I'd feel more comfortable KNOWING it's there for you, so Garden Grocer may be worth the $.
Parmalat make whole milk juice boxes, too. So you could get enough for the whole time, and just chill a couple of days' worth at a time. Nothing worse than milk going bad (although the fat in whole milk makes it stay fresh much longer than skim).