Two things to consider, though the bottom line answer is, yes, those things are allowed.
1) Perishables like butter and cream cheese (and I don't know if that type of milk is more perishable or not)....you must feel very secure in the idea that whatever ice and cooler you have is going to keep them cold. If you have aircraft delays or your luggage is sitting in the sun at your departure airport, any connection point, or in Florida, things can heat up fairly quickly. I personally would feel more comfortable bringing things like that on a nonstop flight, but would more likely just buy cream cheese and milk when I got to WDW. (I personally don't worry as much about butter refrigeration...but that's me.)
2) Between the water and the cooler if softsided and the ice...there is plenty of liquid there that could melt and get onto your other packed items and/or seep through to other passenger's luggage. Please consider double-bagging in plastic anything that might leak/melt.
Have you considered a grocery delivery?