I assume you work in nashville?
I lived in TN for 3 years, 2 in nashville, 1 in Symrna.
What is your route? I don't remember the roads around nashville being very bike friendly, but, it's been 13 years. Maybe it's better.
Anyway, if you can budget the 6 hours a day, go for it a few days a week. I think a better option would be either a car/bike commute, maybe drive into southern nashville or maybe laverne, then ride the rest. Or you could do the alternating bike/drive thing.
Good luck with it.