If you don't want to pay a large sum of money for going abroad, you can exchange it regularly. Don't change a large sum at a time to prevent exchange rate risk, and it is not safe to carry a large amount of cash with you. Every city in Australia has many legal exchange points, including banks.
This is my experience. I have been to more than a dozen countries in Asia, and foreign exchange points are easy to find in cities in underdeveloped countries. The exchange rate of the official exchange point is higher than that of the people, so I still need to find an official exchange.
Now that the RMB is appreciating, don't change too much at a time. Living expenses, if you have found a rental, the living expenses of 800 Australian dollars per person per month will be enough.
As for exchange, as long as you have a foreign currency account, you don't have to go to the Bank of China. The draft of China Everbright Bank will probably do. I know it has outlets in Southeast Asia, but it is estimated that there are fewer outlets in Melbourne, Sydney and Adelaide. In foreign affairs, don't be stingy with the handling fee. To be on the safe side, it's better to use China Bank for remittance.
I estimate that your amount is not small. If you have more than100000 Australian dollars, apply for a VIP card of China Bank. There is a discount.