It would have to be very bad times if NSW had to transfer.
NSW is by far the best resourced state - with 852 staffed ICU beds (current as of today) with 333 tertiary 126 metro 157 regional 197 private and 45 paediatric.
Twice that of Vic - 410 staffed, 145 tertiary, 72 metro, 55 regional, 112 private, 26 paedatric.
Twice that of QLD - 374 staffed, 120 tertiary, 30 metro, 51 regional, 139 private, 34 paedatric.
SA - 170 staffed, 70 tertiary, 16 metro, 0 regional, 77 private, 7 paedatric.
I wouldn't rule it out but it would take major logistics if overwhelmed - with multipatient airlifts making more sense. Probably would require RAAF input. I think the C17 can take 6 ICU patients.
Edit - have confirmed from my RAAF colleagues, RAAF C17 can be configured for 3 maybe 4 ventilated patients.
TM