I'm only a half hour from the Border, and always take the i90 to i79, i77 route. It's the most direct route and takes you through NY, Pennsylvania, West Virginia, Virginia, North Carolina, South Carolina, Georgia, Florida. We usually stop in South Carolina on the way down, that's about 12 hours in, leaving a 7 hour drive on day 2. Depending on the weather, March can be a bit tricky if the temperature's below freezing, especially once you get to the hills in the Virginias. Three years back we drove down March Break, and had -10 C weather in Pennsylvania, but the no real issues with snow.