RonK wrote: I'm not planning a winter tour.

NZ has Febuaury and occasionally the first two weeks in March as summer. The rest of the year is generally either cold or wet or cold and wet, not to mention windy thus by Aussie standards "Winter"
RonK wrote:It also seems that I may be able to get a permit to use the Molesworth and Rainbow roads outside the usual open period. Still waiting for a response from DOC.
It may be fine pushing your bike out of season over the Heaphy. Its a pretty gentle track from my poor memory and certainly not challenging. The estimated time I think is 5 to 7 days but I think I did it in 3 due to being in a hurry. 5 to 7 would be a much more relaxed and enjoyable experience and I dont think having to push a loaded touring bike would detract from the experience.
Actually, from memory again, the Heaphy is propably further north than Wellington geographically and the weather is generally more setttled than the capital.
Spring on the West Coast is probably the most unsettled, wild and wet. That part of the world, especially Karamea is a micro-climate with an abundance of
Nikau palm trees. I favored the Heaphy in winter due to not having to suffer too many tourists due to them tramping the warmer months. There is an abundance of huts for the un-hardy armed with gas cooking and often wood fires inside. I remember some frost on the bivy bag but a decent sleeping bag (down four season) wouldn't notice.

Surly Ogre, Carry Freedom Y-frame Trailer, Extrawheel trailer.