Just a thought?
From memory there is an island about 500k south of Melbourne that started off as a penal colony a couple of hundred years ago so maybe that would be an ideal spot to quarantine everyone who arrives in Australia . Would be easy to set up as they already have had training in locking people up as soon as they arrived in Australia, sure it was a while ago but I'm sure they could restart the locking up process and it's too far to swim to the mainland so there's no escape until the detainees are better.
I hope Scott and Dan read this as it will surely help them.