Upvote:1
As you rightly say in your question, any domestic connection from an international arrival at Auckland airport consists of several steps:
The biggest time sinks in that list are baggage claim and customs on the arrival side, as it very much depends on what other flights have arrived at the same time as yours.
I have breezed through baggage claim and customs in 15 minutes, and I have also been stuck there for more than an hour before. You really cant tell before hand what its going to be.
I have never flown domestically, but security in the international terminal for me has always been a 10 minute process.
Self transfer to the domestic terminal is easy enough - come out of arrivals, turn right, walk the length of the international terminal, cross a road and you are at the domestic terminal. Probably a 15 minute walk.
But there are other considerations - Air New Zealand right now is unreliable because of staffing shortages, with both domestic and international flights cancelled at a moments notice - the staffing shortages also means theres no one really to help you get a refund or alternative routing either. You could arrive into NZ to find your domestic flight delayed by 24 hours or cancelled altogether. Its a right mess at the moment.
Upvote:2
Im going to turn one of my comments into an answer, specifically a frame challenge answer.
Why fly?
Auckland to Tauranga is a 2.5 hour drive, you could easily hire a bus to take a large group, or a taxi to take a smaller group, and not have to worry about any of your concerns. And I bet it would cost less.
Given you are probably going to waste a good chunk of 2.5 hours walking down to the domestic terminal, going through check in and baggage drop, and then security, and then have to wait for the flight - you could already be on the road, seeing a lot of NZ as you go.
The route you would drive is very scenic, you would take the State Highway 1 south through Waikato, and then SH29 over the Kaimai range, which is amazing.
If you wanted to break it up, you could stop at Hobbiton along the way, its a 10 minute detour from your route.