No mechanism in the Constitution for a revote. What would happen, if I read it correctly is that the state legislature (Repubs in all states in question here) would declare the vote invalid, due to it not following the law, then appointing the electors as per the Constitution.
Someone correct me, if I am wrong, please.
You are correct.
When in question, the state legislature chooses the electors.
But no reason the state legislature couldn’t authorize an advisory election as long as it would be completed before the EC meets.