Even if there were a clause in your constitution saying that elections
could be postponed in the event of a natural disaster, that's not going
to resolve the situation.
People would then be arguing over whether or not to invoke such a clause
to delay the election, and whether or not doing that would affect the
results of the election.
In my view, it's better to have the election on the scheduled day and
let the chips fall where they may.
Truth be known, BOTH of your candidates would make for a good president.
They have different slants on the Robin Hood politics of taking from
the rich and giving to the poor, but beyond that, they're both
experienced politicians, they're both intelligent and level headed
people, they both have good advisors to choose from, and they'd both
make good decisions.