Not sure if this is actually going to happen, but in case it does, here are some things to think about.
It probably would make sense to fly to California and spend a day or two before doing the long flight to Sydney, instead of trying to do it all in one day. Find a place to stay at LAX that has an indoor pool, maybe even stay a day or two and see something fun locally. Same for the road home, maybe spend the night and catch some zzzzzs.