Hedging against currency fluctuations
I've considered simply moving my funds to an Australian bank to "lock-in" the current rate, but I worry that this will put me at risk of a substantial loss (due to exchange rates, transfer fees, etc) when I move my funds back into the US in 6 months.
Why move funds back? If you want to lock in current exchange rates, figure out how much money you are likely to spend in Australia for the next six months. Move just enough funds to cover that to an Australian bank. Leave the remainder in the United States (US), as your future expenses will be in US dollars.
So long as you don't find some major, unanticipated purchase, this covers you. You have enough money for the next six months with no exchange rate worries.
At the end of the six months, if you fall slightly short, cover with your credit card as you are doing now. You'll take a loss, but on a small amount of money. If you have a slight excess and you were right about the exchange rate, you'll make a little profit at the end. If you were wrong, you'll take a small loss.
The key here is that you should be able to budget for your six months. You can lock in current exchange rates just for that amount of money.
Moving all your funds to Australia is a gamble. You can certainly do that if you want, but rather than gambling, it may be better to take the sure thing. You know you need six months expenses, so just move that. You will definitely be spending six months money in Australia, so you are immune to exchange rate fluctuations for that period. The remainder of your money can stay in the US, as that's where you plan to spend it.
Current political events
However, recent political events back in the States have me (and, I'm sure, every currency speculator and foreign investor) worried that this advantage will not last for much longer.
If currency speculators expect exchange rates to fall, then they'd have already bid down the rates. I.e. they'd keep speculating until the rates did fall. So the speculators expect the current rates are correct, otherwise they'd move them.
Donald Trump's state goal is to increase exports relative to imports. If he's successful, this could cause the US dollar to fall to make exports cheaper and imports more expensive. However, if his policies fail, then the opposite is likely to happen. Most of his announced trade policies are more likely to increase the value of the dollar than to decrease it. In particular, that is the likely result of increased tariffs.
If you are worried about Trump failing, then you should worry about a strong dollar. That's more in line with actual speculation since the election.
I don't know that I'd make a strong bet in either direction. Hedging makes more sense to me, as it simply locks in the current situation, which you apparently find favorable. Not hedging at all might produce some profit if the dollar goes up. Gambling all your funds might produce some profit if the dollar goes down. The middle path of hedging just what you're spending is the safest if least likely to produce profit.
My recommendation is to hedge the six months expenses and enjoy your time abroad. Why worry about political events that you can't control? Enjoy your working (studying) vacation.