I just had to cancel our trip and I'm busting my butt to save extra cash for a trip in the spring, so this is near and dear to me!

If you're already paid for the trip and just need the travel and incidentals, I think if you really buckled down and made an effort, you might be able to make or save an extra $1,000 for your trip.
Call all of your utilities, services, etc. and ask if they can lower your bill. I did this recently and was surprised to save $65 a month on our cable/internet/phone bundle. I just called and asked, "Is there any way to lower my bill?" and they were great! We didn't drop any services, either.
Have a garage sale. Go through all the closets, toys, kitchen stuff, garage, and pull it all out. We had two garage sales without any big ticket items and made about $500. Most of that was baby clothes at $1 per piece and other baby gear that 1yo DD had outgrown.
Selling on Ebay and Craigslist, for sure.
Check Craigslist for focus groups or other things like that in your area, if you're near a bigger city. I have done these and generally get about $100 for an hour and a half.
Do the envelope system for your expenses and whatever is left at the end of the month can go to Disney.
Pack a cooler for food on the road and hotel snacks, obey the speed limit (use cruise control if you have it) and make sure your tires are full to use less gas, and price out hotels online to get the best deals.
Don't plan on buying a lot of souvenirs. Pick up things at the clearance outlet store and call it a day. (We're not big souvenir people, so this one isn't so hard for me.)
I think you could make it happen.