Nonsense.
When you vote you are voting for electors. Those electors almost always vote for the party ticket they’re pledged to. If a candidate dies prior to the electors voting the party can designate a new person and the electors will (likely will) honor their pledge and vote for the party ticket they’re pledged to. If the candidate is elected by the electors but dies prior to inauguration then the vice-president become president elect.
That would be the orderly way. And Hillary could soldier through it as best she can limp, knowing the business can be turned over to Kaine should her votes carry the race. But will her pride let her plan a transition like this in a graceful manner? That’s a whole ‘nother question.