We ended up with about $1200 in Disney dollars for our trip last December, which, believe it or not, was still not enough to pay for food for our 10 day trip for the 5 of us. It covered a lot of it though, so we were happy.
The way we did it will not work for most people though. First of all, my husband, my oldest daughter and I all signed up for our own cards last fall when they had the $200 Disney dollar deal just for signing up for the card. That was $600 just for that. Then my husband paid a lot of bills from his company with our Disney cards, then had the company reimburse him every month. He is the general manager and CFO, so fortunately he is able to do this. I realize that wouldn't be possible for most people, but it does show that you can get creative. We no longer use that card though, since we have no trip planned.
When we have no Disney trips in the works we always use our American Airlines AAdvantage card to rack up airline miles. We charge everything we possibly can every month but make sure to pay it off every month. I know some people don't believe that there are people who do pay it off every month, but being in finance, my husband would rather die than pay interest to anyone. He would take it out of savings before he would waste money on interest.
In any case, it took us several years, but we did rack up enough miles to fly all 5 of us to Hawaii for free. We never would have been able to afford to take everyone if it wasn't for the reward credit cards.