Yep. As above. Stay longer if at all possible. Tassie is our favourite place on the planet.
Couple of small suggestions:
If you're thinking of the west coast, which is beautiful, check your rig dimensions and the size limits on the Corinna Ferry - see their website: https://www.corinna.com.au/barge-access-and-times. We can't fit on the ferry with our 18'6" ATV.
Secondly, if you're taking the Lyell Highway towards Queenstown, take your time over the steep, windy narrow hill at, I think it's Gormanston. If you've got a UHF, I'd call up and check if there's any heavy vehicles coming over the hill before you proceed.
Have a great trip!