Your willingness to be flexible in location and dates is key.
I am a
DVC member and have the same issue of only being able to plan 60-90 days out - AND HAVE BEEN SUCCESSFUL.
My home resort is the Grand Californian at
Disneyland. There are only (48) rooms and a VERY HIGH DEMAND. This is how I have been successful (and you can too!):
1) Call to make reservation with flexibility in mind (2-3 options).
2) If you can get ANY of the dates that you are requesting, BOOK THEM, and waitlist the remaining days. EVERYTIME I HAVE DONE THIS I HAVE RECEIVED MY FULL RESERVATION WITHIN 30 DAYS....That's been the last four trips.
3) Be prepared with a back-up plan though. You may need to book a cash room for a day or two on either end of your trip if you don't get your full waitlist request.
DVC takes a little work to make it happen each time (on short notice) - I admit! BUT, the savings are INDISPUTABLE. Just check the rack rates at any of the DVC resorts on Expedia.com and then compare the DVC pts at an average value of $10/pt....NO COMPARISON!!!
FINAL PIECES OF ADVICE:
1) YES, buy into DVC - it's worth it.
2) Don't buy A new contract from Disney if you are not going to take advantage of priority 7 or 11 month booking. BUY A DVC RESALE FOR A SIGNIFICANT REDUCTION IN PRICE ($20-30 less per point usually....fewer years though).