don't see why an A320 couldn't comfortably operate into Rotorua (assuming Rotorua is anywhere near 17-1800m). We frequently operate A320s into Aberdeen over here in the UK and that runway is just on 1800m long, no problems whatsoever. In winter we sometimes have a packs off take off because of performance implications of contaminated runway, I think though that the snow that Aberdeen suffers is probably a bit more severe than Rotorua.