Mountain passes across Sierra will be closed, so you can't travel to Reno, as I-80, SR-50 (Sacramento to south lake Tahoe), SR-88 (Carson Pass) will be closed. Even Altamont pass/I-580 had a slide a few days ago. SR-99 will get flooded, as it is parallel to I-5 from Sacramento to Bakersfield. So, expect long delays on both I-5 and I-80, since other secondary roads get flooded.

If you are planning to Vegas, you gonna have problems on SR-152/I-580 to I-5. Also, expect problems on SR-58 between Bakersfield and Barstow on I-15. Even if you want to go to Sacramento, expect long delays on all routes.

Whichever freeway you pick, you will have problems: bad visibility, very slow traffic, partial closures due to puddles, complete closures due to floods (like the north of SFO airport last time).

That's why CHP, Caltrans, NWS advise people to postpone their travel unless extremely necessary. No storm tourism either.