We spent 5 weeks in Tassie from late December to early February in 92/93 I think it was, kids were only 6 & 4 I think. Before going we looked at the options, camping, camper trailer, hire a motorhome but in the end we planned the trip around seven locations (Launceston, Bicheno , Port Arthur, Hobart, Stahan, Cradle Mountain and Burnie) staying five nights at each (except Cradle Mountain it was three nights). We booked into ensuite cabins at caravan parks except for Cradle Mountain booked into one of the chalets and Strahan was a villa.
At the time with the kids we found this to be the best way to do it. Kept the bride happy, made the day to day things nice and easy. Bit of planning with itinerary and the normal travelling logistics made the trip very enjoyable. The 5 weeks made a big difference, while we were still rushed we had time to see most things but still allow for rest days as needed.
We would love to go back to Tassie again and this time stay a bit longer. The longer you are there the cost of taking a vehicle and trailer on the ferry makes it becomes more cost effective. As long as we had the right camper it is how we would do it next time. But the cabins worked well for us back then.