We don't go to Disneyland often, so when we go, we stay ALL day usually from open to close. I have gone a few full days now with toddlers, newborns, and infants and have a good system for not overpacking but figuring out how to pack to keep everyone happy! 

If bottle feeding/Nursing:

•4 bottles per baby (must be plastic, the park does not allow glass), bottle cleaning wipes, breastmilk + cooler pack (find my favorites for all of these at links below)

•6 diapers per child: I know this sounds like a lot but that's about what we go through in a full day!

 •Full pack of wipes: I like a full pack to be used for diaper changes, hand wiping, face wiping, wiping surfaces etc.

•Portable changing pad

•Hats for super sunny days

•1 light blanket per child; I always end up draping a blanket over each kid on the way out and makes for a much smoother walk back to the car

•Stroller fan if stroller naps are anticipated

•2 extra outfits per baby: I like to layer so start in shorts and tshirt, and add on; Extra socks in case they get wet, Lightweight hoodie or long sleeve layer

•Wet/dry bag for soiled clothes

•Charging brick, especially important if you're pumping (1 each for phones, fans, pump)

•Stroller hook or clip for bags; cheap and super helpful if you plan to buy toys/snacks etc then everything doesn't pile in the basket

Be sure to use the Baby Care Centers (free, clean, with changing tables, microwaves, private nursing rooms)