Just another thought...our last two WDW trips, I packed shelf stable milk in our luggage. The brand I packed was Horizon, and we used just regular white milk for cereal in our rooms, but I have seen chocolate shelf stable milk options at the grocery store too. I double bagged the cartons in ziplocks to prevent any explosions in our suitcases. The milk fit wonderfully in the small resort room fridges, and it tasted delish...just like regular milk. Thought I would share this as an option.
Have a wonderful trip!!