Well, it will depend a lot on how many schools are out the week before X-Mas. My kids' aren't, but they'll get the week of Jan 1 off. I wouldn't go that Friday or for the next two weeks. Maybe on Jan 6, we'll go.
Actually from past experience its not too crowded on those dates, its ok , not empty but not chaotic, but head for home before Christmas day its a So Cal tradition to open your presents and head for DL.
Actually, this year our school district in Burbank has the week before Christmas off, so I expect a lot of school districts in Sothern Cal are doing the same. Be prepared for anything, remember it is still the 50th Anniversary