First, I am also going to be at SSR over those dates, and I had to W/L 2 of my 5 nights (in the middle of the stay, and non-consecutive)...I was really surprised...I booked in June for an Oct trip...both W/Ls came through within about two weeks...since then I've thought to add a couple of nights, but those nights still show as unavailable...not sure why things are so booked up that week (F&W doesn't explain it for SSR)...
Second, have you tried calling MS to do a cash reservation? With a W/L back-up? I've done that three times now, and all three times the cash room got replaced w/a points room well before the trip occurred. There's usually (but not always) a DVC member cash discount, and if you go thru MS they can keep the reservation "all in one" (and it happens automatically; you don't have to call to ask for the points nights and the cash night(s) to be linked)...seems like a good back-up plan...
Good luck!