We started HSAs in 2013 as that was the first time it was an option. I looked ahead at when to spend them down. Medicare premiums looked like the best way for us given the amounts we were likely to have saved. Plus easy to document annually. We pay premiums directly from the HSAs. It’s bridging the gap to SS payments taking over plus a bit more.
Similar. 2017 was the first year I worked somewhere with an HSA-eligible health plan. So we're in the $50K-$100K category in the poll. Medicare doesn't start for one of us until next year, then the other the year after, but our plan is the same as yours. Reimburse medicare premiums. We're considering also using the allowed amount for LTCi premiums as well, also easily documented.
Cheers.