Last time they did an evacuation of that area for a storm (12 years ago, or so) it was a total CF. No gas at gas stations, no food at restaurants, No motel rooms available any closer than Tenn.
Tell a million folks to jump in their cars, where are they supposed to go?
And the roads away from the coast became parking lots. Might take more than a tank of gas to go 100 miles.
A few years ago I was driving home from work in central South Carolina and I crossed I-26 on a back country road that never had much traffic as you couldn't get on the interstate from that road. An evacuation was ordered for the coast due to a hurricane and the traffic on the west side of Columbia was STOPPED. That is over a hundred miles from Charleston as you head northwest thru Columbia in the center of the state.
As a few have noted, a lot of people are going to die on one of these mass evacuations that are ordered by politicians that do it because everybody else does it. "Ordering" people to sit on an interstate stopped when a storm comes ashore is stupid.
After a bunch of people die stopped on an interstate, that "lesson" will require the politicians to come up with another way to "order" the subjects to risk their lives for PC. Unless you are in an area that is prone to flooding, I'd stay home and get gas for my generator. A Honda 2k is a hurricane zones best friend in a case like that.
Where are you supposed to go? I'm sure there will be some motel rooms available in western Tennessee.
And for those people with electric cars...good luck!