If the question is a matter of line of succession, wouldn't it just skip to the next person?
I assume so, yup, similar to Henry Kissinger and Madeleine Albright, as they were foreign born citizens. It's more of a theoretical question though, since it's extremely unlikely anyone beyond speaker will ever have to assume the presidency. As cabinet member, a former 2 term prez would for sure not be assigned the role of Designated Survivor during SOTU address to avoid any potential legal issues. But I seriously doubt a former prez will ever serve in cabinet in the near future.
