Yosemite is a large park but only the valley is accessible by road. The valley is a pretty small area, you can drive the loop in 45 minutes assuming you didn't stop and there was no traffic. Yosemite is very popular so traffic can be a problem.
We visited Yosemite last January. We were traveling in California and saw a good weather forecast so we stayed in Angels Camp for a few nights and drove the car over to the park for a day trip. It was pretty nice for winter, 45 degrees and sunny. If your not planning on doing any hiking you might consider a day trip as well. Here's a link to a Yosemite Forum on Trip Adviser. You might look through it and get a better idea of what is available that suites you.
Yosemite National Park Forum, Travel Discussion for Yosemite National Park, California - TripAdvisor
You might also consider a visit to Death Valley. We spent 4 or 5 days there December 2014 and really enjoyed it. There was some flood damage there last year. I think Scotty's Castle was damaged badly and closed. If you do a "Death Valley" search on this forum or look on Trip Adviser I bet you'll find more recent information.