Unfortunately I don’t have much to say about Hanmer Springs because I got sick with a cold and couldn’t go to the hot pools, but as far as I know it was pretty similar to the Polynesian Spa in Rotorua. The trip from the North Island to the South Island was pretty scenic though. In Wellington we got a ferry to Picton cruising the beautiful Marlborough Sounds on the way and then travelled the Kaikoura Highway along the coast to see some seals. It was a long travel day, but it was perfect to just relax and watch the New Zealand scenery unfold. The next day was an even better travel day with views of the Southern Alps and Arthurs Pass, plus a stop to see some greenstones (jade) being carved into beautiful jewelry. South Island is definitely as picturesque as it gets.
Love your posts. I’ve been to all these places in NZ when I lived there. Miss that country so much.