Southern route isn't necessarily the best choice. Ice storms make roads slippery. Very cold & dry snow has a LOT more traction.

I much prefer to drive in very cold than potential icing. (and you do NOT want to be in the South when snow sticks to the road - they have no plows and aren't very good at driving in it)

Be sure you have new wiper blades and your washer reservoir has COLD WEATHER fluid in it. Good for -25F. You may or may not be able to get that at the start of your trip.
Frozen washer reservoir and pump is a bad deal.

Good, deep tread on your tires is important in snow.
And if you've never dealt with it before, it might be worth practicing in a parking lot for 30 min once you reach snow to learn how the car handles.

And a fresh battery in the car might be essential to getting it started if the temp is near 0 or so.