Sorry, but no all-around. The only way to reset the expiry clock is either fly B6 or have the B6 Amex.
As a "hail-mary" approach, (if you're going to lose the points anyways) try ticketing something like JFK-BOS/BUF/SYR, etc.for some day in the middle of winter for 5,000 pts. Maybe you'll luck out with weather, have the flights canceled/ weather advisory go in effect and you can reset the clock that way.
Another option (just as unlikely) is hope for a schedule change and get a refund of your points.