I scored a 50cm model last winter in the deepest hole well upstream in a feeder creek top the Bribie Passage. It was the first hit of the day at just after dawn and the temps were about 2 degrees in the yak. Also in the same deep hole I managed three jew between 75 and 85cm over the next hour and a half with everything falling to 65mm squidgy fish on 1/8 jigs and 8lb braid 14lb leader. Went back the following weekend with opposite tides and only scored two jew under 75cm.
Work those little plastics deep and close to weightless and keep it slowly moving is the clue. Have scored several others in the small creeks in winter time over the past three yrs and all fallen to the same plastics in the same method. Might hit there again this Sunday......
North of Bundy I work the shallows for good jacks in mid winter for good results too. Different technique and different approaches needed though.
Summertime is much easier to score the red fella though.