Forest service has been burning stockpiled wood the past several weeks up in the Portal area, as recently as yesterday (Feb 6), so some vehicles are making it up there.
Here's a picture of the road, from Richard P, who is on a once-a-week Whitney climb so far this year:
Caption: Mt. Whitney from where I parked at the lower campground gate.
Richard's set of pictures is here: Mt. Whitney - February 4, 2012
I can't find the picture now, but some weeks ago someone posted a picture of some rocks, one the size of a wheelbarrow on the road, with vehicle tracks running past. With the burning at the Portal, those may have been cleared. If you go past the Road Closed sign, be wary of incoming weather (vehicles get stuck up there). 4wd would get you farther up.
As for the area above the Notch, I believe people go up the first chute. In the winter, the professional guides set protection up the chute for their clients. Below the notch is not as exposed.
Regarding the Ebersbacher Ledges: In most winters, people can climb directly up over the snow, skipping the Ledges completely. This year the snow may not be heavy enough to cover the brush, so Ledges would be easier. You'll need to be the judge. You can find links to pictures and videos of the ledges in summer in the Mountaineers Route info
post. I think I'd want to be wearing my crampons on the Ledges in winter.
Not sure about snow shoes ...Cottonwood Lakes snow depth guage (See the Mt Whitney Weather link to the left) shows ~24" at 10,000' elevation. You could always carry them part way then decide to off-load them until you come back down.