But it would have to be legal to count ballots in advance of election day in order to have the hundreds of thousands count jump, right? And there would be no reason to do that unsupervised in the dead of night.
I am not sure what you are trying to say.
I am offering that there is a way to "stuff the ballot box", illegally, and get results like you describe.
If someone had access to the machines in the weeks prior to election day, it would be easy. My guess is that bad actors had access, burned fake cards with 10's of thousands of votes, and replaced the "real" cards for election day.
Read the fraudulent cards into the results database - toss the fakes and put the real cards back into the pile.
If anyone audits the cards against the paper ballots, they agree. There needs to be a forensic audit of every step in the process.