I had an award reservation for two weeks from now that I needed to cancel. I called and was going to use my two Plat waivers for this year but the agent suggested we just cancel the flight, leave the tickets open, and call after March 1 to redeposit the miles. Sounded like a good idea so that's what we did.

Of course, it only works if you don't need to use the miles for another ticket between now and then. But I still have the two waivers if needed.