When I drive anywhere outside SOCAL this time of year I always make sure to add my winter kit (a duffel bag with wool & fleece blankets, wool clothing and winter parka) alongside the 96 hr & GHB kits that are always in the back of the truck.
* 96 hour kit is a Rubbermaid container with MRE's and freeze dried dinner entree's, water, a wool blanket, FAK and signalling gear (strobe lights, chemical lights, mirror).
* GHB is basically a Camelbak based kit and includes a PLB -- which makes it all the more of a Get-Home-Bag.
Even within SOCAL there are mountain passes which can become hazardous. But anytime I go that far, I'm leaving SOCAL and probably leaving the state. The winter-kit was put together from extra's with the Siskiyou Mountains (Northern CA/Southern Oregon) in mind.

We often hear/read about folks getting stuck out and about in winter -- it happens and it can happen to any of us too. Being a member of ETS forum is no vaccine to being caught unprepared. I take threads such as this as a serious reminder to not become complacent. Thanks.