Just a thought experiment.
What happens when the mail-in ballots and early voting numbers exceed the number of registered voters for the given voting precinct, before actual election day?
The Democrats will scream "Every vote must counted". And they will be counted.
Guaranteed to happen in selected precincts in multiple States. Happens every election in Democrat strongholds. The Secretary of State will certify the total counts anyway "because the discrepancies are too small to affect the outcome".