Well, the pack didn't work out. Too much nerve pain. But I am not giving up. Somewhere out there is the pack I will use for the trip. Just have to find it.
But I did use my son's backpack for my past weekend adventure - taking a few friends from church into the wilds of West Virginia - the Dolly Sods region to be exact. Made out fine with his pack carrying a hefty load (no nerve pain) but it's older, no hydration sack, no separate sleeeping compartment, and not really a super great fit.
Oh, the joy.