Ah.. life Was so simple..
It's not really viable unfortunately (as well as being 'illegal'... as in similar to not having a parks pass..)
If everything is done properly, transport, permits, passes, food, fuel, proper equipment (inc plb, maps etc), ferry(?), pre/post accommodation(?) so on.. starts to approach the cost and balance the benefits of a guided walk (as well as a lighter pack than could ever be done, even with food drops... someone to cook and clean, get you out of any trouble, (hopefully) tell you what you are looking at, provide company (or not)..) If those with excess energy really want to do this in their spare time then there are (already) ways..
The aarn pack or dehy (from parks or local stores in TAS) are probably good alternatives. Read through some of the ways of reducing weight?
I also doubt the private huts would sell food. A shorter track?