You can reserve now and just keep your eyes open for discounts. You can always switch around reservations later. I think that the dates you are going are still considered "peak season" though.
We just got back from 2 weeks at FW last week - it was wonderful. Still my favorite place to camp!!!!!
No, it isn't too early.... When planning our last trip, I called 18 months beforehand and asked the CM if it was too early to book. She assured me that it was a great idea since lots of people book 3 years in advance. By booking early, I was guaranteed to get the resort I wanted.
As time drew near, I called back and received discounts that were being offered.