Follow up. For the NZ trip, we left the DriDucks behind out of concerns about durability. Took Frog Togg's next better line of rain gear (a 3-ply) which was breathable, excellent waterproofing and windproofing, but… Bulky in pack, bulky under hip belt (it gave me saddle sores), and ultimately not good enough for the severe New Zealand Fiordland rain.
After three days heavy use, I decided to keep the pants for wind protection only*, and left the coat behind in storage, replacing it with a new, very good gortex rain coat (unexpected big expense, argh). *For the next several weeks, till the end of the trip, instead of using the rain pants in the frequent, cold, heavy rain, I wore Ice Breaker merino wool long underwear — every day — under my shorts, in the height of Kiwi-style. I used the pants as wind protection/warmth when stopping or in camp.
Summation: Frogg Toggs/Dri Ducks, fantastic gear if it's unlikely you'll need it very much. And I continue to love the Dri Duck rain jacket as a bike commuting rain coat since it doesn't get any direct hard wear in that use. But too fragile for me to feel safe with it in severe conditions.