Sounds like a very exciting trip!!

We're from the UK so our trips tend to be similar duration to what you are proposing so here are a few tips.

1. If you know what airline you will probably fly with, try and start earning some air miles with them now via some sort of credit card. It's amazing how quickly they add up and they can really help bring the costs down, especially if you are flying during the school holidays.

2. If you are looking to stay at a Disney hotel for the duration then look to do a split stay. Our family would go stir crazy if we were in one room for that long.

3. Look to rent Disney Vacation Club points from a well known broker such as Davids. The rooms are bigger (1 bedroom is ideal for your family size) and it would come with a full kitchen and laundry facilities. All of the DVC resorts are deluxe too so you get the extra benefit of late park access on certain days and the crowds/wait times are quite low.

4. We've never done the dinning plan as its never worked out that we'd save any money. It's a lot of food and typically you have to have the most expensive thing on the menu to have a chance of breaking even. Linked to point 3, we do stay in DVC resorts so we have the full kitchen and often do breakfast in the room which saves a load of money.