Hum....
You yourself noted that Meade would have retreated upon Washington. At that point it does not matter if Lincoln removes him or not the Army of the Potomac is still in place to cover Washington and/or threaten Richmond. It can do both while all the while threatening Lee's lines of communication with Northern Virginia.
To begin with my point was not that Meade would have withdrawn to cover DC, per se, but that he would have had the option of withdrawing to his prepared defensive line at Pipe Creek, which would have allowed him to cover DC. Why would anyone assume that Lee would have followed him there? In what insane world would Lee have followed him there and assaulted a prepared defensive position? Even supposing he could have attacked the AoP and not only defeated them but totally annihilated that army? What good would it have done Lee? By 1863 the fortifications around DC could have repelled ANY army on the face of the earth.
In our hindsight we understand that the Confederacy was being slowly but inevitably strangled by Union forces, taking the Miss R and dividing the South in 2. Advancing on Atlanta and then on to SAvannah and eventually rampaging up the Eastern seaboard toward Richmond. But at the time the attention of the entire world was focused on the 90 sq miles between DC and Richmond. From that perspective everyone's opinion was that not only was the North NOT winning but that the South might easily prevail.
If you could have canvassed any of the militaries of Europe be it GB, France, Prussia, Austro-hungary....the unanimous opinion was that the South had every possibility of winning the war. Ditto for the same governments. The same could have been said of public opinion throughout the North. Ditto for the various state governments of the Northern states. It would have seemed to them that the South could invade the North practically at will, but every Northern attempt is repusled with ease.
The issue for Lee when pursuing the course of action you advocate is that each of those locations is defended at least by Union militia...local state militia if you prefer but they still have guns and they can still shoot Confederate soldiers. This is exactly my earlier point about Lee bleeding his army against Union Militia above. Lee has a limited amount of transport, a limited number of troops and finite supplies of munitions. Even in the best case opportunity of your original conceit, capturing a large portion of the Union supply chain Lee is unlikely to want to squander it on actions of dubious political gain. He has to know that burning northern towns will require both a great effusion of blood on the part of the Army of Northern Virginia and have the potential to inspire greater resolve for vengeance on the behalf of Northerners. Most of whom even in your wildest, most exaggerated imagining he cannot touch.
So, Meade sits behind his line at Pipe Creek. In the meantime Lee burns Harrisburg, Pittsburg, Philadelphia, Baltimore. When the local militia attempts to intervene, don't you think that Lee would have seen them a thank you letter? Lee's greatest strength was his armies mobility. They did not have dedicated supply lines. They could live off the country. Have you never seen comments by the Penn populace on the ANV's soldiers lack of shoes?
New York remains inviolate. Much of the industrial plant of the Union remains inviolate. The bulk of the population of the Union remains inviolate. The Capital of the United States remains inviolate. The means to continue the war, remains inviolate.
If Meade remains behind the Pipe Creek lines NYC is just as vulnerable as any other northern city apart from LA or SF.
Lee cannot perform a reverse Sherman's March because Sherman merely had to reach the sea and he reached resupply, Lee reaches the sea and he reaches...the United States Navy. As, if he is not careful in his burnings, a war criminal, without ammunition. Facing fresh Union soldiers on land and some portion thereof the former Army of the Potomac...perhaps minus the portion that is now marching on Richmond only marginally opposed because...oh yes the Army of Northern Virginia is too busy expending its supply of men, mounts and munitions running amok in Pennsylvania.
The point of Sherman's March was to send a message that by the end of the war Union armies could go anywhere and that the Confederacy lacked the strength to stop them. The whole point of the Army of Northern Virginia is that it prevents that. If it tries running amok in Pennsylvania then it abandons its primary mission. It does not however compel the Union to surrender. Worse it increases the likelihood that the far more mobile and numerous Union armies and reserves can concentrate upon it and destroying it while enabling a bold and imaginative commander the chance to, and let me emphasize this, march a force into Richmond!
Again absolutely right. But if Lee continues to rampage throught out Penn, I guarantee you that Sherman's entire army would have been marching northward to be transported to the east to relieve the threat to DC. This means that the North instead of having taken most of Tenn and Ky out of the Confederate alliance, the border reverts to the Ohio R.
Now it is true that Union often lacked bold and imaginative command but it had deep resources, deep pockets and on its own territories entirely the advantage of interior lines and superior means of mobility that the Confederates enjoyed in the Rebel States...and sea transport which they did not but the Union did. Union superiority in arms and resources did not alone guarantee victory but meant that Lee would need a succession of victories to achieve the kind of hinge point moment the Union was so often a single triumph away from.
You are left with two possibilities. Meade stays behind his Pipe Creek lines, allowing Lee to rampage at will. If so you have the likely possibility of European intervention or a revolt of one or more Northern states who are terrified of the apparent inability of the national gov't to protect them or one or more of the European states (GB and'/or FR) diciding that enough is enough and using their power to end the conflict.
OR Meade leaves his line and opposes Lee on an open field. If he does so who would you bet on--Lee or Meade.???!!!!!