I'm assured that my fears of having to 'run around' are groundless and we should proceed with the trip.
We hire a campervan, which we pick up from the airport - not quite as new as we were led to believe - and it takes a little time to book out, sign, pay, etc, but it's getting late now and we're (that's me) ready to start driving. It's 6.6m long and 2.7m high. It feels like driving a truck, it's got a shower, toilet, sink, cooker, beds and will be the tin can I'm in for an average of 15 hours a day for for the next 26 days.
We decide to head over Arthurs pass, which is a road from Christchurch to the west coast of the south island. I'm hoping we can drive accross the whole of it today. At around 5:30pm it get's dark but I would prefer to carry on driving until we reach a campsite called 'Jacksons Retreat.' Unfortunatley, we have a difference of opinion as my travel companion strongly objects to 'driving at night and missing the views.' This turns out not to be the last of our disagreements but I'll refrain from chronichling.
We 'free camp' (that means staying in the campervan but not at a camp site) in a lay-by on the side of the road for the night. There is enough water onboard to have 3 very quick showers and to be able to wash dishes, etc in the sink. The heater and microwave only work if the campervan is plugged in at a campsite. It's a little cold at night so the hot water bottles we bought will turn out to be handy.