I have actually just booked this air nz flight from PPT to AKL then onwards to MEL, we are travelling with a 6 year old boy now so I can anticipate what will happen that morning with a 3.10am departure.
Just posted on another old thread with my queries, that it appears there will be no lounge access as well as Air Tahiti Nui lounge closes before midnight. I think the early check-in is most likely not gonna happen, so most likely will just book the motel across the street and checkout at midnight. Well that's my plan so far...