I would be as flexible as possible with the West Coast airports and include LAX as well as SAN in your searches. [They are not that far apart]

Personally I would look for Club award availability and then use book and upgrade to put the MFU through when you buy the tickets. That way you know you will be in CW.

Also, although the Christmas sale can be good, it can also see BA take down a lot of reward inventory that then reappears after the sale. However, although WT+ prices may look tempting, if there is no CW award availability at the time, you cannot be sure what will appear later. That's OK as long as you are happy to fly WT+ if it doesn't work out.

Though others have said that the rewards map in not reliable, no-one has pointed out that all CW availability can be used for WT+ upgrades.