How he would have responded publicly is meaningless.
Had those tens of millions of votes been cast in person, they would not be subject to scrutiny and potential elimination.
Axios reports that Trump plans to declare victory on Tuesday, should an early vote count show him ahead. He says ""I think it's terrible that we can't know the results of an election the night of the election. ... We're going to go in the night of, as soon as that election's over, we're going in with our lawyers."
Instead of "fight the enemy where he isn't", they walked right into his hands.