1

I would go North, the West Coast is much better North to South. Not sure about camp sites but with school holidays over I have a suspicion you should be ok without bookings. It is much more fun to be flexible.

Just north of Kaikoura there is a place on the left where you can do a nice walk to a waterfall. The pool at the bottom of the falls is where juvenile seals hang out while their mums are out at sea hunting. Nice walk and well worth the half hour stop. I can't remember the name of the place but ask around in Kaikoura, someone will know.

If you have time, from Nelson head up to Nelson Lakes National Park, even if just for a picnic lunch.

On your way south of the glaciers (or even while there) make sure you visit Lake Matheson, great views of Mt Cook and if the weather is right it will be reflected in the lake.

Have fun, and please, if traffic starts to queue up behind you pull over where safe and let them pass.

2

It is unlikely that camping sites will be booked out.

With four weeks you can easily to a loop up to Nelson as suggested, down the west coast to queenstown and back up via mt cook.

3

picnic lunch at Nelson Lakes? Only if it is windy, otherwise you will not want to sit still. The NZ state bird will see to that. :-)

lovely place though.

4

4 weeks you should be able to get around the south island, we did the trip in january. we didn't book any accommodation in advance and that was holiday time in NZ. if your van has a toilet you are able to "freedom camp". we headed north from chch and did the anticlockwise loop, don't miss the Catlins, its fantastic.