VBHB, getting back up north is possible but there's no way of guaranteeing anything. Patience would likely be required.
TSRABECOMING, the roster you work very much depends on where you're working & the ratings you hold. Not all towers operate 24 hour & at night sectors get combined. We generally don't work block rosters (who wants to work a block of the shifts they hate) & there's limited scope for swapping shifts. Shifts are typically 7 or 8 hours but can be up to 10 hours with a minimum of 10 hours between shifts. Averages to 10 days per fortnight.
I have all ratings in my group & my roster is mainly variations of morning, morning, afternoon, afternoon, night, night, off, off, off. Those without all the ratings don't do nights.
There is great variety because the rosters are tailored to handle the traffic patterns. For instance Perth traffic is handled in Melbourne so the peaks occur 2 or 3 hours later than local Melbourne time.