I'd book SSR GV at the 11 month window, just so you have something. Then, at 7 months, start calling day by day.
We wanted a 2BR @ BWV last Fall during the F&W Festival. I booked a 2BR at OKW at my 11 month window. Then I called BWV right on the 7 month dot. I ended up booking BWV that day for 4 days in a row of the trip and keeping OKW for the other 4 days in a row. I stayed on the waitlist, and slowly but surely, all the days became available at BWV...the day before we left, the last day came up at BWV!!!!! As a day at BWV became avialable, I'd take it and cancel the OKW day. I just made sure that the days that kept coming available at the BWV added on to the "string" of days I already had there...we were not going to bounce back and forth between the 2 more than one time!