With kids in the L.A. area, we frequently drive from the peninsula to L.A., so here are some comments...
I'd leave at 11, not 12, depending upon how comfortable you are with driving after dark & areas that you aren't familiar with & traffic & whether you stop to eat. The sun sets at 4:50PM. The grapevine isn't the worst part of the trip unless you've hit snow or bad weather. But if you're not familiar with the roads, the traffic can be a bit distressing. I do find the driving habits there to be a bit different than in the bay area.
Drive time to the outskirts of L.A. depends mainly on your speed on I5 and where your destination is. In the greater L.A. area, NYE should have relatively light business traffic, but by 7PM, you will get social traffic (based on what I hit on Friday nights). You might also hit congestion between SJ and Gilroy, or Gilroy to Los Banos, but that's gotten a lot better than years back.
FYI, if you're heading east on the 210 from I5 towards Pasadena, get over to the right in plenty of time before the exit to 210 (a mile ahead). You do have to cut across merging traffic to get to the exit. Even though I've done it a number of times, it always concerns me. I believe there is still construction in that area. (Also, if you're heading into Pasadena, there is a quirky spot you need to be over to the right just as you get to Pasadena. It is as if you have to exit the 210 to stay on the 210.)
If you drive after dusk, fog is a risk at this time of year. Don't forget about wind warnings too (see below) and construction.
I'm curious. Did I miss any mention of the Rose Parade, or whether the band is in it? Usually the two teams' bands are in the parade. I stayed on Colorado Ave a few weeks ago and out of curiosity, asked about the pricing of the hotel (far east Pasadena): minimum 3 nights, total about $800.
A resource is
Â
http://www.dot.ca.gov/hq/roadinfo/Hourly
Also,Â
http://quickmap.dot.ca.gov/
For instance, currently it says:
Quote:I 5
  [IN THE SOUTHERN CALIFORNIA AREA]
  IS CLOSED TO SOUTHBOUND TRAFFIC FROM WESTERN AVE /IN GLENDALE/ TO
THE JCT OF SR 134 /IN LOS ANGELES/ (LOS ANGELES CO) FROM 0100 HRS TO 0400 HRS
ON 1/28/12 - DUE TO MAINTENANCE - A DETOUR IS AVAILABLE
  THE NORTHBOUND CONNECTOR TO EASTBOUND & WESTBOUND SR 134 /IN LOS ANGELES/
(LOS ANGELES CO) IS CLOSED FROM 0001 HRS TO 0500 HRS ON 12/28/12
- DUE TO CONSTRUCTION - A DETOUR IS AVAILABLE
 A HIGH WIND ADVISORY IS IN EFFECT FROM 5 MI NORTH OF CASTAIC TO THE
SOUTH JCT OF SR 138 (LOS ANGELES CO) - TRAVEL IS NOT RECOMMENDED FOR CAMPERS,
TRAILERS OR PERMIT LOADSÂ Â
  [IN THE CENTRAL CALIFORNIA AREA]
  NORTHBOUND TRAFFIC IS REDUCED TO 1 LANE AT THE JCT OF SR 43 (KERN CO)
24 HRS A DAY 7 DAYS A WEEK - DUE TO CONSTRUCTION
  NORTHBOUND TRAFFIC IS REDUCED TO 1 LANE 10.5 MI NORTH OF THE JCT OF SR 58
/AT LERDO HIGHWAY/ (KERN CO) - DUE TO A BIG RIG FIRE