I am being told that Charleston and Morgantown are supposed to be the end-of-2016, West Virginia, 1-2 punch.
In some ways - I would have thought that a Supercharger at the area of the split South on Highway 19, off I79, at the Sutton Area would be a good connection to Wytheville, VA, from Cranberry, PA.
Go Mart, at 3157 State Street, Gassaway, WV 26624, USA Puts Cranberry SC at 177 miles North, and Wytheville SC at 149 Miles South.
Going a bit North: - Giovanni's Pizza, Coffman Square & Rt 5, Burnsville, WV 26335, Changes this to 160 Miles North, and 166 Miles South! Between them - both good possibilities - at least in terms of distance for the North-South Run, if there is no Morgantown, SC!
https://goo.gl/maps/cUrN55hnpA82 (327 Miles from Cranberry, SC to Wytheville, SC)
Substituting a New SC in Morgantown, at Bob Evans, 10 Lawless Rd, Morgantown, WV 26501 - changes the Direct to Wytheville run:
87 Miles Cranberry, SC to Morgantown, SC, and
240 Miles from Morgantown, SC, to Wytheville, SC! (327 Miles from Cranberry, SC)
The Charleston Run South from Macedonia SC, could be something like this:
119 Miles to Lori's Family Restaurant, 17020 Mcconnellsville Road, Caldwell, OH 43724 >
113 Miles to Shoney's Charleston (Near Charleston Civic Center), 116 Kanawha Blvd E, Charleston, WV (232 Miles from Macedonia, SC)
https://goo.gl/maps/cYbmyTLNwAu
From Cranberry, SC to Wytheville, SC, via a Morgantown, SC, and Charleston, SC (Per Example addresses, above), would be:
87 Miles - Cranberry, SC, to Morgantown, SC, and
155 Miles - Morgantown, SC, to Charleston, SC,
129 Miles - Charleston, SC, to Wytheville, SC.
https://goo.gl/maps/EsQzNq4Hwok (371 Miles from Cranberry, SC to Wytheville, SC, an extra 44 miles)
However, adding in a Morgantown, SC, makes it just 146 Miles (from the Bob Evans Suggested location) to Hagerstown, MD, SC!
However - I drove that route, it has a large amount if hill climbing and elevation changes! It might be a good idea to put one in near
Fairfield Inn & Suites Cumberland, 21 Wineow St, Cumberland, MD 21502.
That would make the trip:
80 Miles - Morgantown, SC to Cumberland, SC,
67 Miles - Cumberland, SC to Hagerstown, SC.
https://goo.gl/maps/7hdYyk494RH2 (Just adds 1 mile - at 147 miles)