Driving from Melbourne to Brisbaine in two weeks' time. Then flying to Cairns for three days.

Bringing a 9 or 12 just in case. 78kgs. Which would you guys bring?

Here in Florida I can get by with just a 9 during our winter since it's either blowing 17+ or not much is going on.

After researching a bit it looks like if it's rideable and blowing out of the east then it's 10-15 and not much more.

A 4/3 or 3/2 wettie? I figured I needed the 4/3 in Mel, but then once in Syd and N. I could use a 3/2 instead? I'd rather pack a 3/2 and be cold two or three days in Mel than having a 4/3 to paddle with if there's surf toward Syd since more time will be spent N. of Brissie during the two week drive.

Thanks for any help.
Cheers