Do you think we should waitlist for another resort?
Well, you already have a back up at SSR, so that's covered. You are allowed to have two active waitlists, but I think you have already used them for the two studios.
FWIW, I wouldn't give up the SSR reservation unless both studios come through. If you haven't already, be sure to call MS and make sure that there are notes on BOTH studio waitlists that the SSR reservation should not be canceled unless both come through. If you need the points from the SSR reservation to reserve the studios, I'd cancel the BCV waitlists altogether - the chances of both coming through at the same time are virtually zero and you will run the risk of having no where to stay. Not a chance I would want to take during Presidents' week. You could change the waitlist to a 2 bedroom which would improve your chances (only need one villa, not two).
If there is someplace else you'd rather be than BCV or if you just prefer not to be at SSR, you could cancel the 2 BCV studio waitlists and use your two waitlist opportunities somewhere else.
If you are willing to stay together in a 2 bedroom, then you could have two waitlists. Perhaps the larger resorts would give you a better chance - say savanna view at AKV or Lake View at BLT or OKW or Pool/Garden view at BWV.
Again, FWIW, trying to get two waitlists to come through (especially for a popular time at a small resort) is a long shot and is more risk than I'd care to shoulder. I wouldn't do it if I had to reuse the points from the back up reservation to reserve the studios if the waitlists work. Chances are that you'd end up with one studio and no 2 bedroom. UGH!
My advice is to cancel the waitlists for the studios and either keep the 2 bedroom at SSR or keep the SSR 2 bedroom & waitlist for a 2 bedroom somewhere else. Chances of something going wrong with the current situation are good, IMO.