It will depend on whether one of the pacific storms blows thru or not. If so, we get snow all the way through March. Otherwise all roads are open and clear.
There are currently ice patches in some higher elevations, generally about five thousand and up, that can make road treking quite dangerous. You just have to keep a close eye out and beware on north facing slopes. That said, there are plenty of lower elevations to enjoy.
Basically you break it down into which direction you're heading. We can get a start and then maybe more of the locals will chime in.
There are four basic routes out of the LA basin where we can list roads and routes to seek out. A Buttler map would be a good source of routes to seek, they've already rated the best touring and scenic roads in the area.
Here's a start
NORTH - over the grapvine
Frazier Park, Pine Mountain Club to the 33
Up 101 to Ojai and north, or continue to Santa Barbara, 154 route north
Malibu, Malibu Canyons, Rock Store, Neptunes Nest
NORTHEAST - Cajon Pass
Glendale Mountain Road GLR (Asuza)
Angeles Crest Hiway
EAST - Inland Empire, east of Riverside/San Bernardino
Hiway 15 to Temecula then east to Julien, Borrego Springs, the whole plateau up there
SOUTH - Orange County, San Diego County, and routes heading east along the way
South Main Divide