You've got to be careful not to make so many rulers that you don't go flying at all. Icing is an interesting thing. less than 500 ft can make the difference between accumulating ice and melting it.
You need to READ the forecast and make judgments based upon it. Canberra in winter is always going to be a liability. Similarly, in winter its probably better to think like a single engine VFR flight and go for longer tracks to stay on flatter ground.
In winter the cloud is usually lower and 10,000ft will get you above it most of the time (and therefore out of icing if it occurs). This still leaves the descent. But you can mitigate that by looking for holes, fast - direct descents and potentially alternates.
Interestingly, if you read William Bucks book on early airline flying, the captains in the era of the DC4 & DC6 made the same decisions.
The best advice I have been given is that as soon as any ice forms you should do something. Climb, descend, turn, something. Don't wait for ice to limit the aeroplane's performance. You can request cruise at non standard altitudes. if the LSALT is 4100 ft and you get ice, then cruising at 4100 ft is an option.
In the US where the FAA seem to have a greater concern with safety rather than bum covering rule making, there is a wealth of training material on their website. The US AOPA have this guide
404 Error - AOPA and I have a nice little book īn flight icing"by Perkins & Rieke that I got from Sporty's.