My ex husband and I spent three weeks in NZ in February, 2011 when the weather was near perfect. Sadly, the only wet few days were when we visited Milford Sound. Apart from the first night, when we landed in Christchurch, we didn’t book any hotels for our visit. 10 days after we left Christchurch they suffered the second catastrophic earthquake. That affected me deeply, not least the resilience of the people and the leadership demonstrated by the mayor.
Apart from landing in Wellington when the place was almost fully booked up due to a convention, we had no problems in securing accommodation on spec. We hired a car and used the ferry from Picton across to North Island. Before boarding, we returned the car then hired another in Wellington.
In six weeks you should be able to see plenty! Highlights for me were Christchurch, Dunedin, Queenstown, Frankton, Fox Glacier, Milford Sound, Kaikouroo (whale watching), Wellington (especially the cable car ride to the botanical gardens), Napier, Rotarua (geysers, etc., a Maori evening, St. Faith's Church), Waitangi, Whangamata, Coromandel Peninsula and the Bay of Islands (dolphin watching).
The scenery was stunning with beautiful vistas around every corner! But you’ll already know that. The people were friendly and welcoming. On one one occasion, we had stopped to take photos of unusual trees when a local stopped to check all was well! So kind!
It's one of my favourite destinations for a holiday. I’m sure you’ll have a memorable time. Good luck in the land of the long white cloud!