The options for Lee were very limited. Who ever attacked would lose. Unless we are talking about a first day victory ending with Ewell taking Culp's Hill. Then we are talking about a moderate Confederate victory with the near destruction of I Corps and badly damaged XI Corps.
But Meade is left with falling back to his original defensive positions of the Pipe Creek Line, a far stronger position even than Gettysburg. And he has 1st Division VIII Corps to call on to help build up a full corps from what's left of the two smashed at Gettysburg. Also, a rail line that runs directly behind his Pipe Creek positions affording the easiest possible re-enforcement of troops and supplies directly from Washington, including possibly XXII Corps, even VII and IX Corps if Halleck releases them (as he well might, considering the circumstances).
When you add to this Lee's "Victory Disease", started at Fredricksburg, reinvigorated at Chancellorsville, and now heightened to a hyper level by an ATL Gettysburg victory, what kind of madness will Lee come up with for Pipe Creek? The terrain there just doesn't allow for any flank attacks whatsoever, only head on charges into the open against heavily prepared positions. And Lee showed he was more than ready to launch such assaults BEFORE Gettysburg! After winning it? Battle of New Orleans, anyone?
I don't see much happening in Pennsylvania itself after this. Stuart's men were utterly exhausted, and Lee's goal was the destruction of the AotP, not prestige victories further north. There were 20,000 militia under General Couch approaching central Pennsylvania that, while they couldn't stand up to Lee's veterans, could certainly hold off (and did) raiding parties heading for Harrisburg.