To set the stage, Hooker has just been defeated at Chancellorsville, Lee begins his movement North.
When Hooker first assumed command of the AoP he had established a line of direct contact with Lincoln in order that the hostile Halleck might intefere as little as possible in Hookers command. After Chancellorsville, Lincoln pointedly, reestablished normal command relationships and instructs Hooker that all further communications will be through normal command channels i.e., Halleck and the Secy of War.
Halleck and Stanton withhold any major reinforcements to replace the losses of the Chancellorsville Battle (the same ones, that were later rushed to Meade's assistence)
So without firm backing from Lincoln (which he has lost), Hooker cannot and does not expect any timely assistance from his immediate superiors.
One of Hookers complaints is that he receives no help from Halleck, whose only actions are merely to vetoe any and all of Hookers plans and ideas.
In actual fact from the time Hookers receives news of Lee's movements, his own movements are rather more quick than most today realize, (his only orders are to keep between the ANV and the Capital and /or Baltimore, he can get nothing more precise out of Halleck or Stanton or, presumeably, Lincoln)
Hooker uses his newly reconstituted cavalry fairly effectively. Although Pleasanton cannot break thru Stuarts screen, his efforts have the effect of screening the movements of Hooker and thus Lee has no better idea of where the AoP is than Hooker does of the ANV (although, over time, being in Northern Territory, Hooker is more likely to gain timely intelligence than Lee)
The fact that Hooker is not recieving adequate or timely reinforcements and knowing that Halleck and Stanton are out for his scalp, Hooker IMO, would make the same deduction that Meade, did, concentrating the AoP would almost certainly draw Lee to him.
Again, the Pipe Creek Area would catch his eye as the best place to, not only effect the concentration but also, to fight on.
Hooker would certaiinly have his cavalry out and would, I think, find the ANV approximately where Buford did, but Hooker IMO would fight defensively (lack of adequatesupport in Materiale, manpower or from his immediate superiors).
Lee would still be distracted by the loss of Stuart and his logistical and supply problems and would most likely insist on the offensive as the logical solution to his problems (much to the annoyance of Longstreet, even at Pipe Creek) With time, supplies and ammunition running low and approx. 10,000 Union cavalry under active commanders, time consuming flank attacks was not commendable to Lee at Gettysburg, nor would they be at Pipe Creek, IMO.
In all likelyhood, we, today, would be celebrating the great Union Victory at Pipe Creek and would still be considered the high-water mark of the Confederacy.