I was just doing to suggest buying it in the parks. Unless you have a freezer to freeze ice packs, it will be hard to keep cold. You could consider giving her milk at the resort for morning and night and milk at each meal and just fill her cup with water during tour time. Another idea is the shelf stable milk boxes. Try them before you go as some kids (mine included) do not like them. Milk is available all over the parks. One last suggestion is if she is still on formula, leave her on it a bit longer if the trip is coming up soon. Nothing magical about switching at a year old. Both my boys were well past a year old and we delayed with the blessing of our dr.