With certain seating configurations the aircraft is capable of flying beyond the airline's current longest flight from Auckland to Chicago, putting New York within range. Qantas uses Dreamliners to fly from Perth to London, 250km longer than Auckland-New York flights.
The engine maker that has won the Air NZ deal will also be in town on Monday. Both Rolls-Royce and General Electric have lobbied the airline to power the new planes.
It is one of the biggest calls made by the airline in more than 15 years - when it first ordered Dreamliners. It now has 13 in its fleet and another one to come as part of that order.
The total value of that commitment including the engines and the maintenance agreements is more than half the $3 billion market capitalisation of the company.
A leap to an Airbus A350-900 or A350 -1000 for its next wide-body plane would have been a bigger call. Although Air New Zealand uses narrow body Airbus planes on domestic and short haul routes, it hasn't used the European-made planes for long haul operations.
The airline's board had discussed the fleet replacement on six occasions.
There will be some sensitivities around opting for a Boeing given the tragic fallout from flight stabilisation software problems on new 737Max aircraft. However, Dreamliners are much different planes, and after some teething problems have had a good safety record and use different systems.
McDowall said the 777X was not out of the picture long term and could be a replacement for the airline's 777-300s.
The aircraft announced on Monday will have new cabins with the airline doing work now on replacing its business class seats.