We prefer to sit max. 2-3 hours daily in the car, pref. less as we noted last time in the South-West that there is a lot to see along the way. In that perspective, I was thinking of even dropping Shenandoah N.P. and move towards Lancaster on day 6. On the other hand, some fellow travelers in my group read a blog of someone going from Washington downwards to Orlando in 16 days and taking the plane back. Any thoughts?