Let's face it: no matter how hard Peter FitzSimons tries, Australia is not going to become a republic. Australians aren't that passionate about who the head of state is; they know who runs the country and that is the Prime Minister. You can have all your theories about constitutions and representative democracy and blah blah blah.
Point is, the British monarchy ain't going anywhere. Once the Queen dies there will be a King, then another King, then another King (most likely). Australia still loves Prince Harry and Kate and Wils and the bubbas.
However! Should those flaky Poms forget themselves and throw a major fit - because of the debacle that will be Brexit - and elect a socialist, vegetarian, terrorist-loving socialist, aka Jeremy Corbyn... well then...
QE2 can come 'ere!
Seriously. Corbyn is a republican who wants away with the royal family and wants them replaced with a President. Should that occur then the President of Britain will be the President of Australia. How stupid is that? Let's take their Queen.
It wouldn't be the first time someone from Britain came to Australia and found themselves in paradise. We wouldn't even have to change our currency!