May is not exactly a peak demand time at DVC accommodations. We toyed around with staying in a Studio last May before deciding on a 1B. We could have taken a Studio at either BWV or BCV, and that was between 3-6 months prior to our travel dates.
All indications are that BWV and BCV are a lot harder to book than OKW, so I don't think you'll have a problem.
We've done this every week for the last 3 years (a couple times were even Memorial Day week) without a problem. And once we've been able to add days on very short notice (about a month out).