I think the Google Maps numbers for travel time will be pretty accurate. As you plan your stopped time (gas, meals, etc.) I wouldn't discount a few stops in pullouts. It is, after all, sort of the point of the whole thing. +1 to what varider says.
Mid-week is a great idea. Weekends are a pain with all the extra sightseers.
I tried to ride the whole BRP+Skyline 2 years ago. Got socked in with heavy fog at higher elevations, then some rain, and some road construction. So I bailed after about 1/2 of it. Have alternate plans.
Skyline Drive is 105 miles at 35mph. Net - 3 hours driving. I bang it out now and then on a big loop, usually on a crisp cool morning when I'm not working and most others are. I don't think it is boring, unless you are stuck behind a minivan.
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