I look at it this way:
Best win:
for Wake would be Georgia Tech
for GT would be UVA (assuming the 6th win is against Duke)
Worst loss:
for GT would be Wake
for Wake would be Northern Illinois.
Based on that (and GT will sell more tickets*), I think GT will be chosen over Wake.
*If the Queen City Bowl (or Charlotte Bowl, whatever it's called) is choosing between GT and Wake, then Wake will be chosen based on the proximity to the school.