Louisville is roughly the same distance from Nashville as is Owensboro. So as far as the drive from Atlanta goes, it is the same distance. In One-Iron’s case I would suggest coming up I-65 instead of branching off onto the Parkway in Bowling Green to Owensboro. Stay in the Louisville area on Friday Then go to Owensboro on Saturday.
Nashville to L-ville = roughly 2.5 to 3 hours. (175 miles)
L-ville to Moonlite= about 2 hours on the KY side (2 lane most of the way on US 60) A bit easier to use I-64 in Indiana where the road is better.