If you look at public behaviour here and elsewhere, especially America, I think there is only limited acceptance of lockdowns and once out of level 4, you would practically need martial law to get back to it. Only widespread deaths across the entire population would change the public mood. People simply are not taking this seriously enough. For better or worse, it is very much a one-way street.
So long as we keep up testing rates and reinforce the message about personal distancing etc, then hopefully we'll be able to ring-fence outbreaks.
We actually managed to do it despite having a huge influx of imported cases while facilities were nowhere near the capacity and ease of access to testing we've got now.
It's been shown (not just by NZ) that C-19 can be contained. I think we'll be okay. Level 2 is okay - it seems almost normal out there, the few shops etc I've visited - everyone was doing the right thing.