In some severe snow storms chains may be absolutely required in California, otherwise you’ll have to wait for snow plows or better weather; either that or buy a set of chains along side the road. I had that problem one time during a freak Oct snow storm on I80 Donner Pass, bought a custom-fit set and they installed them for me while I sat inside w/the heater on, along side I80. Priced about the same as if I had purchased the set at a parts store, and what w/the custom fit, that method worked well for me. Note this may not work for you if you get stuck in a place where purchasing chains isn’t an option. In that case you’ll just have to wait.
I70 to I15 to Las Vegas then to LA might be a better winter-driving choice, less chance of severe snow.