The best way to explore Aotearoa New Zealand is via campervan, or in your case with an RV if you’ve got kids along. 6 weeks is enough to see a lot of the country. Usually folks go from auckland and head south or Christchurch/Queenstown and go north. Rentals are sometimes cheaper if you start south and end in Auckland. Be sure to go south of Queenstown and north of Auckland too.

Hotels and restaurants are expensive here plus you need a vehicle to get to most places, and with a few exceptions you can sleep in your vehicle anywhere or at free / nearly free in city centres.

Also the hiking trails are amazing. There are 1000 government run huts along the trails where you can stay. They’re great, but you need to make reservations in advance for the great walks, which are worth it. There are also great cycle routes, you can usually rent bikes and get pickup/drop off. They’re worth doing, especially the lake dunston trail.