New Zealand looks small on the map. It isn't. Driving from Auckland to Queenstown by motorhome is roughly 1,500 km plus a Cook Strait ferry, and the speed limit on State Highway 1 is 100 km/h. Most first-timers underestimate drive times by 30-40% because they forget the country is mountainous, two-lane, and full of single-lane bridges. The honest minimum for a North-to-South trip is 14 nights; 21 is more comfortable. For a single-island sampler, allow 7-10 nights.
How long do you actually need
A useful rule: plan around 200-300 km of driving per day, not 400. That gives you time to stop at the things people fly across the world to see — Hooker Valley at Aoraki, the Pancake Rocks at Punakaiki, Cathedral Cove on the Coromandel — without arriving at the next holiday park at 9pm. A 14-day South Island loop from Christchurch covers Kaikoura, Nelson, the West Coast glaciers, Wanaka, Queenstown, Milford Sound and Tekapo without feeling rushed. Trim that to 10 days and you'll skip either the West Coast or Milford.
When to book the motorhome
For the December-to-March peak (NZ summer), book the vehicle 5-8 months out. Cook Strait ferry crossings sell out for January and Easter — book those at the same time as the motorhome, not after. Shoulder season (April-May and October-November) you can usually book 6-10 weeks out and still have a choice of layouts.
What to figure out before you ask anyone for a quote
Three things make trip-planning conversations productive: a rough month (or two-week window), pickup and drop-off city (Auckland, Christchurch and Queenstown are the three main depots), and party size. Everything else — vehicle layout, route shape, ferry timing — flows from those three.