I don't agree with the sharing of a capsite option. It's just not fair. Many of us have to scrape by for years to make a trip to WDW. Yeah it's expensive, but if staying at FW is a must for you, I'm sure you can scrape up the extra $$ if you really wanted to.
You only want to stay 2 nights, and it doesn't sound like you want to visit the parks, so you only need about $150-$200 depending on the site you want.
There are many ways you could come up with that much, in a short enough peroid of time, to not have to wait until fall.
Some suggestions that I have used myself to help my family save the $$$$
Try not eating out as much,
Selling unwanted stuff on E-bay,
If you use a credit card, get a Disney Visa, and use it to pay for as much as you can -bills, groceries, ect. Just don't overdo it, and make sure you keep the balance where you can pay off the total when it comes in every month (you get Disney reward dollars, that are good for anything Disney, including a campsite, I'm sure)
There is a thread on here somewhere about the craziest thing you are doing to save money for Disney, you may find some helpful hints on there.
(I don't know how to post the link, someone who's computer savvy help me out here)
Don't get discouraged, and don't think that everyone on here is out to get you, there are very friendly and helpful people on this board. They have helped me out on many occassions. I just belive most of the people on here belive as I do, that you should do as the majority of everyone else does and sacrifice what you can, for the reward of FW.
If you can't come up with the $$$ take your kid to the park or the beach. My kids would kill to live close to the beach, and save your $$$ for FW for next year, add a day at MK while your at it. Saving and Planning is 1/2 the fun. Okay planning is 1/2 the fun, the saving sucks, but we do what we can for the mouse!