I know you said you go to California pretty often, but two thoughts come to mind -
1. Head to LA and make it a "movie" weekend. Many of the films contending for Academy Awards are released into LA theaters in advance of general release, so they can get in under the New Years deadline and be seen by Academy members for Oscar voting. Visit the Chinese and Egyptian theaters, hit some museums, walk along the Strand in Hermosa and Manhattan Beaches, chow down in Koreatown or... well, whatever. Good weather, endless options.
2. Head to the Monterey Peninsula. See the (amazing) migrating butterflies in Pacific Grove, visit the aquarium in Monterey, head to Santa Cruz for fun food or the boardwalk amusement park (open on weekends in winter) or visit the Big Basin redwoods up the road. Or head to Salinas for the Steinbeck center, or down to Big Sur for lunch at Nepenthe. Or go farther down past Big Sur to Hearst Castle (if you haven't visited it, it's time you did.) On the way you could stop at Point Lobos - incredible scenery and wildlife, or stop at the elephant seal breeding/birthing beach just north of the Hearst Castle turnoff. You could fly into either SFO or San Jose - SJC - and be in Monterey in under two hours.
Butterflies at Pacific Grove -
Elephant seals at San Simeon -