Before the Buffalo Supercharger was available I stopped to top off in Ellicottville at a 30Amp Chargepoint charger and took the 219 route. I did not range charge and left with 20Km short of a standard full charge thinking that I that would be all I would need... I was wrong and almost ended up stranded and 9 miles short of the Somerset charger. I basically "glided" into Somerset showing "0" range and plugged in with minutes if not seconds left before the car shut down.
It is a very nice drive... very hilly and curvy through the Allegany forest. We also ran into heavy rain and borderline freezing conditions which I believe also affected my range significantly. If you have a 90D, range charge, and you are going during the summer you will probably be fine but it is awfully tempting to drive overly enthusiastic through these curvy roads and kill your range.