You are asking a question that I bet a lot of people are going to have at the end of the year. You have just thought of it sooner.
If the market is down in December, and if you do not have enough cash inside IRAs to protect stocks from having to be sold to pay the RMD, that would not be ideal, of course.
I would ask an accountant about whether an “in kind” transfer would be a way to pay the RMD based on the amount of the face value of the stocks transferring. (If you can do in-kind.) But later if you want to sell the in-kind shares, I have a feeling they come in dragging their cost basis with them, thus invoking a cap gain tax. Possibly a biggun. You should find out about that.
Dividend investors can let some of that income accumulate in cash inside the IRA and then use it for the RMD when the time comes, so they don’t have to sell stocks to pay taxes. That cash is like a moat around the stocks to protect them from having to be sold or transferred out to a taxable account.
(If you are charitably inclined anyway, look into using a QCD for part of the RMD. The advantage of the QCD is that it is not added into the AGI. But it would not help you keep your stocks. It would just save some income tax.)
Sounds like you are in “Be Prepared” mode. What you are talking about here (in May) will probably sneak up on some people in December.
Get professional advice and good luck with finding the most effective thing to do. (And maybe think about building that moat of cash inside an IRA. Even though the ROI on cash is absurd, your stocks would be protected.)
You probably already know that if you have more than one traditional IRA, the total RMD from all of them can be paid out of just one of the accounts. (Check me on that one, too. But, so far, I am not writing these posts from tax jail.)
Boomer