Bringing this back up one more time.

Yesterday I opened a Fidelity HSA. The balance is currently $0.00 but that will improve when I start to transfer funds from the Optum Bank HSA cash balance at some point soon. I won't liquidate the existing investment unless forced to do so as it's currently in a low-fee Vanguard S&P fund that's no longer available.

Thanks for the responses on this subject. The HSA seems to be a good vehicle for saving in a tax-advantaged account for later for folks who aren't large consumers of health care.