yangotang, welcome to
posting on FlyerTalk!
Since your chief question has to do with what UA would do in regards to a dropped return, we are going to move this onward to the UA forum from the California forum.
However,
Ocn Vw 1K has given you good advice about other possibilities for intra-California travel, and you might want to pursue those on those airlines' forums.
cblaisd and
SanDiego1K
Senior Moderators