What your suggesting is General Lee perform what Sherman did to Johnston in the Atlanta Campaign and out flank Meade to make him abandon his defenses.

With well over a two to one superiorty Sherman could afford to detach a Corps to swing around Johnston. Lee did not have that advantage. Stuart was a division sized unit and there were equally sized Union cavalry units by the 3rd lurking in the Union rear and could have protected Meade's supply.

The problem with this is it comes down to numbers. Lee didn't have all of his forces, as opposed to the number of Union forces, at the right moment to perform such a manuver.

David