We did this Viking cruise in March 2020. We arrived in Auckland a few days early and booked a wonderful tour with Auckland Scenic Tours - Hobbiton/Waitomo Glowworm Caves Combo. They picked us up at the hotel (we stayed at the Grand Mercure Auckland) early in the morning in a shuttle bus. We were the first tourists to arrive in Hobbiton and hardly anyone else was there. We got some great photos and, if you are a fan of the books and movies, it was almost like being in them. The glowworm caves were very interesting too. The day was the highlight of our trip.
We also had some independent tours booked in Tasmania, Melbourne, and Sydney. Unfortunately, Covid hit, and Australia closed its borders. Our cruise ended just as we were arriving in Tasmania. We had to cancel the rest of the tours.