In the short term, I don't think non-incumbents at age 81 are likely to be electable as presidential candidates in the current era. In the long term (perhaps a couple of decades?) I think the "soft cap" will slowly rise towards 90 as a significant minority of superagers have alawys remained capable of running up until then. People like the current Malaysian PM who can keep going well into their 90s are astonishingly rare, though.
In the really long term, I'm an optimist about ways in which we might learn to change the ageing process, and if that's vindicated, the limit will go through the roof.
