Check out Heritage Museum of Orange County. They’re technically in a commercial area, so I believe they allow receptions to go until midnight. Great pricing and the required caterer has delicious food (and great pricing for open bars!).
Where in SoCal are you located? Take a look at eventective.com and partyslate.com for information on curfews and whatnot. Unless you are in an isolated area (no nearby neighbors) outdoor venues tend to have noise restrictions after 10pm. So your best bet will be places like Quail Ranch or Hummingbird Nest in Ventura County. Not sure what is available in other areas that is similar.