We stayed in each place two to four nights. We tried not too have many long drives; the longest was the day from Motueka to Oamaru, crossing almost the complete South Island. This was a full day driving, and we chose to do that because we judged the mountains and glaciers less suitable to visit with small children, but we did want to go to the southernmost part of the country and we did not want to skip Abel Tasman national park. The other drives were between two and five hours, which was OK as long as we rested frequently.
From the North to the South Island we took a flight (getting a new rental car on the South Island). We considered taking the ferry, but the ferry schedule was inconvenient for us. A flight is hardly more expensive and much faster.
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