Originally Posted by
kiwi_norway
Funnily enough, I was just on the phone to the NZ call centre in Auckland when you wrote this.
They called Heathrow operations, who advised that even as separate bookings, "as long as both sectors were booked on Air NZ ticket stock", they'd be happy to book me all the way through. Bless 'em.
Will give an update in a few weeks, once I've seen it actually work.
Glad to hear that logic and customer service has prevailed. I hope it does work out, but I would plan for the worst - try to go carry-on only if you can.