The other thing to keep in mind is as the vaccine is rolled out and as the percentage of the recipients increases, you might find that the requirement to quarantine will probably change from mandatory hotel to being able to be done at home, this in itself will allow an increase of travel inbound, although probably initially not tourists, more like returning citizens and students. You will then find vaccinated Australians will be able to apply for a permit to leave and travel.
So around July you have the situation crossing over from what we have now to what will become the new new norm for a while until it can be fully opened up, my guess would be about this time next year.
WA will be sometime around 2050.
Caveat being this is applying commonsense which has been lacking with the current bunch of Australian politicians.