Welcome to Tripadvisor Virginia Travel Forum..
May I suggest you also open a new thread (inquiry) on the Road Trips Forum, members can offer quite a bit more info.
Weather in Virginia in December can be quite varied, we could have rain, cloudy, fog, icy, snow, or a mix, & then there is the chance it could be a lovely day.
You could also just ask in both the NJ and PA forums. And..go to "google maps" and type in from Long Island to Verrazano Bridge. Then zoom out. Looks like you could take I-95 to DC, then 68 over to 81. But...95 does go all the way to Florida.
Keep looking at www. weather.com for the forecast. Safe travels!
So I'm thinking your trying to avoid some traffic and "incidents" on the roads and that's why not 495W from LI and no 95S. Is that the idea?
So you wouldn't want 78 to Harrisburg PA where you can get 81, is that right?
How soon do you need/want to connect with 81?
You could do something like 95S to Levittown NJ area dn E on 276/76 to Harrisburg PA where you can get 81S.
That said, remember 81 is in mountains. Beautiful drive in good weather but tougher in bad weather. I hated the deep foggy days and nights on 81 head north after Harrisburg PA but you won't go that far north. Chatanooga area can have fog for some reason. 81 is plowed well as a major business route and is sort of kept clear just with a tremendous amount of traffic but be aware of any ice if it's freezing out.
And trucks. They have saved my life being able to drive behind them at times in the fog and blizzards. But they can be scarey so be aware their traffic seems to pick up as the day goes on.
I can't fathom why you would want to use I-81, which follows the ridge of the Blueridge Mtns. with all the potential weather and roads problems that would entail, when you could use I-95 along the lowland coast and not worry about ice and snow, not to mention more direct, even to Fla.s west coast.
Also keep in mind that I-81 has statistically TWICE the ratio of tractor-trailers in the mix, than most interstate highways.
"that I-81 has statistically TWICE the ratio of tractor-trailers in the mix"
We did not know this, but we "feel' this to be true.
Long ago, I-81 was a pleasant drive; today we avoid I - 81 b/c of the trucks.