The bulk of the Army of Tennessee was moved from Mississippi to Augusta in less than 20 days in January-Feb 1865. The two corps that were part of the initial movement were plagued by desertion and probably lost 30 percent or more of their men along the route. Nevertheless, at least 8000-10000 infantry were started on their way in late January, and at least 6000 or so were available in SC by early February. The movement was pretty impressive given the broken nature of the rail network in Alabama (no continuous line), and additional breaks in GA as a result of Sherman's march. The rail network between Macon and Virginia was in much better shape in September 1864 than the rail/riverboat connection between Meridian and Macon was in January-February 1865. I believe that a large number of soldiers from the Army of Tennessee could have been moved from southwest Georgia to Virginia in a relatively short amount of time in September 1864. The Army of Tennessee had just under 43000 infantry and artillery according to the September 20 1864 strength return; with each corps numbering between 13000-15000. On a side note, this illustrates the extent of the loss in the Tennessee campaign; Hood lost 2/3rds of his infantry and artillery between September 20 1864 and January 20 1865.
I'll opine that a move by Hood to assist VA could have happened.
Hood moves north declaring a "march on the Ohio" (something he actually did later), Hood himself marching into Middle Tenn, while half his force moves into East Tenn. Hood blusters about Kentucky while his East Tenn. column marches north, feinting but never attacking any Federals.
The East Tenn column gets to SW VA and most get on the rail line to Danville. Small detachments, though, would make noise west and north, as if rejoining Hood. Early is informed of something to be in ready for, but no details. Early is ordered to play dead for a while.
If Early is inactive the Federal VI Corps will be sent to Petersburg.
18,000-20,000 men of the "Tenn. Corps" will be moving behind Early from Lynchburg.
Early gets details, and a "Cedar Creek" occurs that has the Confederates in overwhelming force. Despite the CSA deficiencies in cavalry, Sheridan has to withdraw to protect DC., and reform a shattered army.
Early leaves a feinting force to make noise in the lower Valley, while he leads 25,000 men on the flanking march against Meade at Petersburg, a few days before the Federal elections.
Or, something.
This COULD have happened. But variables cannot be factored as they would be unknown.
It was very possible for Lincoln to be very inconvenienced right before the Presidential election, though.