Actually, you could replace her after the election. Remember, you are voting for an elector, NOT the candidate.
The elector, while bound in several states, could vote for someone else with little risk to themselves.
So, technically, they could put someone up for election as late as Jan 5th, (when the votes are counted in DC.)
They can’t replace her name on the ballot...even now. What electors do is another matter entirely. And, the primary point is that Nov. 1 is a meaningless date. That date has no bearing or significance whatsoever. Her name is on the ballot no matter what.