From Dublin it's a pretty quick drive into gold country and the high Sierra. Head out 580 to either highway 4 or highway 108 (or do the tourist thing and take highway 120 to Yosemite). Check out the gold rush town of Columbia off highway 49, or keep heading up into the spectacular Sierra. You can be in some remarkable wilderness in less than three hours drive from Dublin.
Bryan, if you decide to head into the Foothills a nice loop is Sonora to Columbia State Historical Park and then up HWY 4 to Calaveras Big Trees State Park. You can then head down HWY 4 to Murphys and Angels Camp. Continue west on HWY 4 to Stockton and back to the Bay area. If you decide to come to Columbia, shoot me a PM and lets see if we can meet up.

Regarding travel into the Sierra in December: If you want to go to Yosemite or higher up 108 you will need to carry chains (required in Yosemite). Yosemite is gorgeous right after a snowfall, so if you keep an eye on the Yosemite forecast and are flexible, a quick trip to Yosemite Valley can be rewarding.
--P