We faced this dilemma on our trip last year. I went to target and paid for a refillable water bottle with built in filter. They will give you free cups of ice water in the park at any concessions stand or counter service restaurant. We started out with our bottles filled with ice water from the resort and then just asked for ice water during the day and filled them up. Total cost for three bottles $30 Total cost for ten days worth of water $FREEEEE saved us a fortune! Plus we have the bottles to take back with us this year. Drugstore.com has them for $8.99 with free shipping on orders over $25. Another tip since extra bags are so high to check, ship yourself a package to your resort, they will hold it for you until you arrive. Also check out Gardengrocer.com they will deliver to the resorts for $12 and have pretty much everything you can get at the grocery store, milk, fruit, cereal, juiceboxes, etc. We used an electric hot water pot to heat water for instant oatmeal and hot chocolate in the room for breakfast and took a loaf of bread in a plastic shoe box for pb and j sammies for kids snacks, also packed muffins, pop tarts and snack pack cookies and crackers in the plastic shoe boxes from the dollar tree, just tossed them when we left.