Southern California includes a range of communities, each with its own population and its own set of residents facing similar decisions. Recognizing that scale can be oddly reassuring. It means systems and providers throughout the region field these same questions regularly. You are not an outlier for needing information or reassurance. Your situation is common enough that thoughtful answers exist if you look for them.
Whether you ultimately choose something close to Ontario, CA or consider a location like Desert Hot Springs, CA or Palm Springs, CA, the decision remains yours. Regional context can inform your choice without dictating it. You get to decide what proximity, setting, and structure mean for your own life. Nobody else can make that tradeoff for you. Trust your own read of what fits your circumstances.