If you are staying in backpacker hostels (usually the best option in NZ, they invented them), you will probably run into travelling folkies everywhere. Just carry an instrument as needed (buy a cheap one in NZ if you don't want to fly with your usual axe).

In Rotorua, we ended up staying at Spa Lodge, which is pretty cheap, dead friendly and more or less a throwback to the 1970s. Has its own low-tech sulphurous hot tub at the bottom of the garden, piped straight up from Hell daily. You never know who you're going to meet in a place like that.