How are the fares looking compared to what has been available in the past? If they're decent, why wait? If you end up having to cancel, you get a credit, same as you have now. If fares go down, you could cancel for a credit, re-book at the lower price, and retain the excess credit for another trip.

If you're already sitting on WS credit that you would be using to book this trip, there doesn't seem to be much downside to booking now.