I am heading from Southern Utah to the East coast after Christmas. I am trying to bag some state highpoints on the East coast. Is it possible to hike the highpoints of: Georgia (Brasstown Bald), South Carolina (Sassafras Mountain), North Carolina (Mount Mitchell), Virginia (Mount Rogers), Tennessee (Clingman's Dome), and possibly Kentucky (Black Mountain), voer the break?
What kind of mountain conditions can be expected for late December/ early January on these peaks?

Right now the weather is hellish. Unless something changes really fast the peaks will be snowless. The only ones that would pose a problem in snow would be trailhead access due to closed roads--Clingman's Dome and Mount Mitchell. You'd have long approach hikes in case of road closures.

The sixers (and Mount Rogers) can get really kickass cold if the weather turns. But mainly not.