I note with some interest some of the proposals being promulgated here. The use of mining villages would be a nightmare. The purpose of quarantine is to isolate the infected person from the community, AND ALSO from every other person in the same facility. Anyone who has worked FIFO at a mining compound will know just how claustrophobic Dongas are, and would be quite unsuitable for isolation purposes.
Think facilities that (a) offer a modicum of comfort (you are going to spend 14 days cooped up); (b) have a series of rooms that can isolate persons from one another (even floors) and (c0 offer the logistics of rapid medical intervention if needed plus food and ancillary support. So the Hotel property close to to the entry point seems the most logical option (unless you utilise all the unoccupied prison cells - dooh! there are few of those and even then most 'inmates' are not in lockdown 24/7.
The mismanagement of quarantine has been about the human factors - minimum wage individuals working 'security'. Perhaps an ADF/Borderforce management would be the better option.
Those who propose regional / remote locations (including for crew) - be careful what you wish for.