The Brisbane cyclocross season doesn't start for another 5 months, so why not check out the Brisbane South MTB Club Summer Sprints series.
The races are a short course XC setup at Underwood Park. The course is flowing with a few rocks and small drop offs, so cyclocross bikes will be fine. They are 2 races down but there are 2 to go. Dates for the remaining races are, 18th of March & 1st of April.
Check out the website for more details.
I will be there.