Yeah, I really can't either. But my income is in dollars, so if the dollar-to-pound exchange goes badly enough at some point in the future, I may not have a choice. Then again, there's always the EU....
Finally pinned someone at my old work down. Turns out that they give retirees a $3,000 HSA, funded through the clearinghouse company they contracted to. The retirees have to buy a medicare policy through the company. If there's money left over, they can use it for other medical expenses, or roll it to the next year. Spent 30 minutes this evening, most of it on hold, trying to get out of the company how they will handle retirees who are abroad permanently. They refuse to discuss until 90 days before I would be enrolling.
So, I contacted someone at the Uni's retiree center. Who has just informed me that because I am out of the country, the Uni will NOT be giving me the $3,000 HSA - since they don't require me to have Part B unless I'm in the country. They definitely will require it if I ever come back, to keep my medical coverage with them. So, I can either pay for Part B ($134 a month thrown away) out of pocket when the time comes, or I can deal with the penalty for getting Part B late, if I ever have to go back.
Kinda stinks, as I could have used the roll-over of funds to build up enough to pay for other needed medical care, down the line. Then again, the clearinghouse wouldn't even tell me what the typical premium through their organization cost. Entirely possible the $3,000 a year wouldn't cover it, the way medical insurance goes, in the USA.
Guess I'll have fingers crossed and go without part B.