As Good a Way as Any to Start a New Year
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With reasonable stops for food and fuel, and allowing a little time for traffic around Washington and getting through New York to JFK. I think you're looking at a minimum of 14 hours to get from Charleston. So if you leave early on the 30th from Charleston and have two drivers, you can just get into the airport area that night and get some sleep before your family arrives.
On the way back you have a few choices. You could, if you want to have the chance to see some snow, come down the Appalachian Mountains, basically following I-81 to Knoxville and then I-75 to Florida. But I suspect that the best parts of that trip such as the Blue Ridge Parkway will be closed, and it is a bit out of the way. If you haven't seen enough of America's historic large cities, you could retrace your steps down I-95 but make time for stops in Philadelphia, Baltimore, Washington and Richmond. Finally, although it would be too cold to do any swimming, you could take a slow drive down the coast taking in the Delmarva Peninsula, the Outer Banks, the Grand Strand and the islands off the south coast of Georgia.
AZBuck