I've been on the Saw Mill plenty, I used to go that way to get to Westchester Medical Center.
I-80 today though is pretty bad, depending on time of day of course...
I-84 to I-81 is just super easy for us, we're 8 miles from I-84. Then I-81 takes you through PA, WV, and VA into TN(Johnson City), then into NC via I-26 to Asheville. Brevard is less than an hour from there. 12 hours any way you slice it.
There's also the fact that we're going to western NC and you were going to the SC shore.