I have stayed a most of the Hyatts in Southern California (I miss my Diamond status ). The Andaz and a 3 year old would not make a good match. Do the HR Mission Bay. It has a great pool area with slides that kids love. The Park Hyatt Aviara isn't really near anything, good hotel but the location is not condusive to visiting "touristy sites." While LEGOLAND is nearby, check your kid's height to see if they can even ride anything. https://www.legoland.com/california/...actions/rides/

The HR HB is an interesting option. The hotel is actually across the PCH from the beach, but there is a bridge to avoid the traffic. What would you want to do with your days there as HB and the OC in general aren't really known for their tourist attractions. Maybe visit Balboa Island in Newport Beach or head to Long Beach for the aquarium and Queen Mary?

The Indian Wells resort isn't anything special, unless you plan to golf, but the desert would have a better chance of clear weather. The night will be cool though. There is a great childrens museum out there (https://cdmod.org/) and zoo (https://www.livingdesert.org/). I would look at the Palm Springs Hyatt, too. Palm Springs does a great street fair on Thursdays that is right outside of the Hyatt. villagefest.org