Hi Ozza, what time of day did you see this ant? There is a night/twilight active species that looks like this, but also another species that is active during the day. My guess is that it is the night active Myrmecia pyriformis, as it stays active over the winter period.
Without a better close up photo, it's a bit hard to tell which it may be (hairs on the postpetiole/gaster = M. pyriformis, no haris = M. forficata). Even though it was active during the day, I've also seen M. pyriformis out and about in the day during winter. To be safe, I think we may have to go with Myrmecia sp.