If you want to go in the fall, Disney almost always has free dining. It would mean pulling your kids out of school, but if you're okay with that it would save you a lot of money. Yes you would pay rack rate for the room, but with six people eating for free I still think you would come out ahead. The only issue could be that Art of Animation is not usually part of the promotion, but you could try for two connecting rooms in a value resort. Our family loves having the dining plan, but we have only gone during free dining, I don't think I would pay for it since I am sure we could eat less expensively on our own. But for us, if we are able to get it free it beats any room discount we've seen for our travel dates.
I will also add, that I am a stay at home mom and I save a good chunk of our vacation money myself. I take out all my weekly money in cash (money for gas, groceries, misc expenses) and whatever I have left at the end of the week gets added to the Disney fund. Sometimes the amount left is pretty low, but other weeks it's pretty good. I aim for at least $20 a week, but I'm often able to do more than that. I also shop at a grocery store that has a rewards program, like spend $100 in a month and they give you $5 off your next order, or spend $30 in produce for the month get $3 off your next order. I generally do several of these promotions each month and at the end of the month I use all the money back to buy a Disney gift card. This week I bought a $25 gift card and only spent about $10. It's not a lot of money but it adds up. We also save change. That doesn't add up to a ton, but it's probably a couple hundred dollars each trip. I use that for souvenir money. I'm also just getting back into swagbucks, and I like that. I don't earn nearly as much as other people on here, but every little bit helps. If you do online shopping remembering to shop through swagbucks, ebates, or mypoints to get the points/cash back, is really easy and takes no effort.
We also have a certain amount come out of each of my husband's paycheck to go towards vacations. And regardless of where we go on vacation, I always spend a bit of time shopping around to find the best price. We love to travel, but could not afford to do so often if we had to pay full price. Finding discounts really makes our vacation money stretch further. Since you have over a year to plan and save, I think you could do it, especially since you'll be able to put some of your work money aside for it.