Agree with your other points on acting, but disagree on the timing.
While the chance Congress/Pence does the right thing on 1/6 exists, it is a mere chance. To see what's up on 1/6 changes the optics from bad to awful, as the available EO action will be viewed more as a reaction, if the fraud is allowed to stand.
I think Trump acts prior to 1/6. The EO is decisive as opposed to passive watching COngress. The EO prior to 1/6 would be viewed more as pro-active to fix the fraud than reactive to a bad 1/6 vote.
Indeed, the EO at any point does not have to "decide" the race, only to defer it to a new vote in these 6 or so states. If Biden wins the re-vote, he is POTUS.
We still need to call the GOP Congress members and ask them to reject the Democrat electoral votes from the swing states.