Crazier things have happened, and there is a 10:55pm one still too, so I would try for both if I were you, and if not try again tomorrow morning. Sometimes other non-revs get sick of waiting and just give up and don't show and whatnot, and late night connections are always more open to people misconnecting not far behind very early morning flts.

That being said, I would say try tomorrow for a while if tonight is a no go, and then once you start getting around the afternoon, I seriously would consider just renting a car and whatnot and driving to LAX. Tomorrow the flt to SYD is very open, you will get on if you can make it to LAX tomorrow for sure barring anything catastrophic like the LAX-SYD being cxld tonight (no reason it will)