A few years ago, after I hadn't stayed at Hilton for over a year, I received a letter from HHonors that may points would expire in 60 days. I called HHonors, and the CSR said that I could keep my account active, without the points expiry, by requesting a replacement HHonors membership card. He had a new card mailed to me, and the points stayed in my account for another year. Don't know if that method still works, but it worked then, for me. Worth a try though, just ask.
bj-21.