PX has a very strong (and air travel dependent) domestic market. They also own most of the domestic fleet.
There have been adjustments to the international network (no more SYD, HKG, MNL, NRT or NAN) so there will be some slack in the Boeing fleet, but it is small and manageable. Arrangements and protocols are already in place for crew traveling to sim in Australia.
PX will weather this fairly well I suspect.