I don't think anyone mentioned it, but you can buy everything you need for a decent breakfast in the resort gift shop. They have cereal, juice, milk, bread or bagels, pop tarts, cream cheese, peanut butter, jelly, cheese sticks, granola bars, lunch meat like Oscar Meyer Bologna. Lots of choices and you don't have to worry about grocery delivery or going out to the store when you get there.
Our faves for the quick in-room breakfast are cereal, bananas or peanut butter and jelly sandwiches. If you don't have a fridge in your room, then you can pick up a smaller size milk so you don't have to store it.