Hobart Tasmania to Queenstown NZ

Your only option is to fly and it would be either via Melbourne or Sydney or possibly Auckland ( possibly seasonal direct flights on Air NZ).

There are no ferries between Australia and NZ.

Sorry Paula but no Oz to NZ ferry. Tassie to NZ is at least 3 times further than the overnight ferries you mentioned.
Spirit of Tasmania goes from Devonport in Tassie to Geelong in Victoria (an hour from Melbourne).
I think that is a 9 hour journey dependent on sea conditions. Bass Strait can be very bumpy sometimes.

Much quicker to fly.

You should be able to get a cheap flight from Hobart to Melbourne, less than an hour in the air.
Melbourne to Queenstown is about 3.10/15 flying time.
A few options.
One day of travel, morning flight to Melbourne. Head through to International and get on an early pm flight to Queenstown. Remember 2 hour time difference. It does basically write off the whole day with travel.

Morning flight to Melbourne, spend afternoon and evening in Melbourne. Next morning flight to Queenstown.

Spend extra time in Hobart fly to Melbourne in the afternoon, sleep in Melbourne and then fly to Queenstown next morning.

Of course a longer stopover in Melbourne is another option.

JetStar has a relatively cheap flight connecting thru Sydney.
Qantas has a couple of early morning flights that connect thru Melbourne, and which arrive in Queenstown by mid afternoon, ie around 3 PM. It'll cost about $100 more for the one-way ticket.
It'll be a full day of travel no matter how you slice it.

Thanks for the replies! As always, you are very helpful. We are going to fly to Melbourne and then spend at least a day there. Then head on to Queenstown.

Thanks!

Just be aware Paula Tasmanian school holidays finish 27th April, ours here in Victoria finish 21st. Huge public holiday Anzac Day 25th April. Massive AFL games in Melbourne.

OH! Good to know. I'll check those dates against my itinerary.

Thanks!