I lived in Tassie for 13 years (Ulverstone) on the North West Coast; I can tell you categorically that they have one of the best managed restocking systems around. The fishing is exceptional both lake, river & sea, although January is not the best time for the lakes.
You will need to contact the Tassie Fisheries Dept to check on the closure of some lakes. Is your dad ex military by any chance as there is (almost free) accommodation at a couple of good fishing lakes. I found wattle grubs the best bait for Brownies & Rainbows while grasshoppers worked extremely well in the rivers.
There are numerous lakes & rivers to fish in Tassie, how are you travelling around Tassie?
Gear, I have caught some beautiful Trout on cheap & expensive gear, believe it or not I have caught one of my best rainbows on a "Strawberry cream", yes the Allen’s lollies.
Launceston would be a pretty good base although Swansea would give you the best of both worlds.
Let me know if I can help further, oh bye-the-way January can be pretty dam hot in Tassie, be careful as you will end up looking like Lobsters!
Cheers