When we vote for the president we are actually voting for the electors. The process should end right there - no need for them to revote in December. If there are 270+ republican electors, game over and, of course, ditto the other way around. All this speculation on how the electors will vote is horse excrement.
The U.S. Constitution states otherwise.
It would require a Constitutional amendment to implement this. I don’t disagree with your idea, but for practical purposes this is what happens anyway. While there have been faithless electors, they have been few in number, and nowhere near the 37 that would be needed for Trump to lose his majority.
The Constitution requires them to vote, in their respective state capitals (precisely to prevent tehm from congregating in one place, which would make corrupting the process easier.)