For 21 days, you may want to plan on getting a full kitchen and getting groceries and cooking at least 1 meal/day and having snacks/drinks. That will bring down the sticker shock (which honestly, you may not actually have high enough for 4 Disney adults at 3 meals/day at Disney)...that's 252 restaurant meals (without counting any snacks/drinks), and if you are not sticking to CS, that's gonna explode in cost fast in Disney parks...and even if you do stick CS, you're talking $15-$20 each (without drinks)...