We broke it into nine days. Average 40 miles per day, but some days were in the 20's, last day was over 60 miles, including getting to the hotel.
There are some very tough (at my age) hills (i.e. south bound into Cumberland) and some REALLY steep hills getting to hotels. Williamsport is like San Francisco...who knew?
Paw Paw, and the Paw Paw tunnel were great (in a down to earth kind of way), and the Levi Mansion is really something worth seeing.
We went a few weeks ago, great weather, aside from one day of rain (uphill into Cumberland).
It is amazing how close to big cities you are, but how undisturbed the settings are.