Hmm I could only really give personal answers so I will provide this link about the legal consequences - https://oag.parliament.nz/2013/drink-driving/appendix3.htm as to whether these sentences are considered harsh or not, I'm unsure. They're all I know!

I can comment on our culture though - we have a nasty drinking/driving history and while things are changing, we lose hundreds of people to driving related incidents each year, in 2017 about 50% of those were drug/alcohol influenced deaths. That article also suggests making the alcohol limit 0 for adults which is the current rule for teenagers which I honestly wouldn't mind. But I rarely drive my car, I live in a small city and I walk everywhere I need to go so this wouldn't impact me in any real way.

We do have some stellar ads around drink driving though, etched into our lexicon almost a decade down the line -

My parents told me when I was about 16 and heading off for a booze cruise with my friends, how impressed they were that our group always, always, always has a "sober D" and that in their day it would just be a matter of the least drunk driving everyone home. So hopefully we're on the right path culturally.