How often do fully booked rooms become available?

[BensWife]

We have a 2 bedroom villa booked at OKW, but what we would really like is a 2 bedroom villa at WL. Were thinking about CL, but would like to do a villa instead. We are not DVC members and aren't renting points (everything I read said you have to be 11 months out to do that, and we are 5 1/2 months out). Do you think something will open up? How often do I need to check the website to see? Thanks.