Went with DH, DS4 and my sister for 8 nights last fall. From home, I brought napkins, plastic cups, disposable travel cups, dishwasher tabs, foil, Clorox wipes, single-use laundry detergent packets and dryer sheets. I did a load of laundry while eating breakfast, then started the dryer and dishwasher before we left for the parks. I brought a bag of coffee and filters from home, since we each drank at least 2 mugs every morning. I wish I'd brought a baking pan because I like to bake bacon in the oven to cut down on mess. I recommend bringing beach towels for the pool, as well as floaties or other pool toys, as they are pricey at the resort, but you can buy them cheap at Walgreens. If you plan to use the lazy river at Tower 5, make sure to bring innertubes for your smaller kids. I brought snacks like individual servings of Goldfish, granola bars, applesauce pouches and candy from home.
We went shopping at the Publix on 192 after checking in and bought OJ, fruit juice, bananas, chocolate milk, creamer, Eggos, bacon, pancake mix, almond milk and frozen fruit for smoothies, iced tea, beer, and some chicken fingers and macaroni and cheese from the deli. Bought rum from the liquor store next door. We ate breakfast in the room every morning to save money and time, and lunch/dinner a few times. I know plenty of people hate doing this stuff on vacation, but for us it meant we were able to pack fewer clothes and could splurge on 2 nice TS meals, instead of all QS meals that week.
Make sure you check your appliances when you get to the room. I had to dump out my smoothie and eat in the park our first morning because the motor had burned out. They brought a new one that afternoon but it was a minor inconvenience.