NZ Honeymoon in October?

My fiancé and I are trying to pick a location for our honeymoon. New Zealand seems like the perfect mix of the types of activities we would look for in a honeymoon (hiking, wine country, great scenery, boat rides, etc). Our very tentative itinerary would be spending most the time on the South Island and 1-3 days near Auckland.

We also think if we don’t take this trip now, pre-kids when it’s easier to fly across the world (we live in the US), we may not go until we’re near retirement and less able to do all the outdoor activities we want to. We get married in early October and have a strong preference to go on our honeymoon right after the wedding (October 4-18th) instead of going back to work and delaying the honeymoon for a few months. All that being said would we be dumb to waste our big splurge trip going to NZ in October? Our other options are to wait and go over the Christmas/NY holidays or in February or to choose a new location. The former has the big con of not getting to go on our honeymoon right after the wedding so we may lean toward choosing somewhere else.