Winter Highpointing in the East is fun and can be challenging. Depending on current conditions road closures are always a possibility. Clingman's Dome road is closed during winter months, however I have parked at Newfound Gap and hiked up the road during winter. You could also follow the AT up from the same parking area. You might need snowshoes. About a week before you head East, check individual area websites and search for local conditions. Mount Rogers for example will close access if temperatures and wind chill factors meet certain criteria. Black Mtn. road will probably be plowed but could be icy. Brasstown Bald might provide a nice winter hike from the visitor center if the road is closed. Again it all depends on conditions at the time. Send me an email and I can give you updated info before you leave.
Happy Trails and Safe Climbs