I don’t know much about the Californian climate; you’d need @Tom or @Yvonne G for that expertise.Would a heated house that’s protected from rain and allow them to come & go be sufficient for keeping them outdoors through these colder months?
In theory, with properly heated and insulated accommodation yes you can. Have a look at what’s done with Sulcatas as they cannot hibernate so must be kept active and eating all winter.
The alternative is fridge hibernation so you guarantee temperature stability. Some have reported that doing this even for a couple of weeks helps the tort reset for being awake