Race co-director Warren Bates said the decision had been driven by event entries exceeding expectations and by the successful launch of the Corporate Challenge event, run in conjunction with the Starship Foundation.
"It's fair to say that Chapter One - the 2012 event - generated a huge amount of interest and that's flowed through into the next instalment.
"With the corporate challenge now in place, it has meant that we can consider wrapping things up for GodZone Chapter Two much earlier than expected."
Mr Bates said strong demand from overseas teams had continued, with almost 40% of entries from international competitors, covering South America, Europe, Scandinavia, North America and Australia, along with teams from this year's event.
Teams included Seagate, the adventure racing world champions, and Scandinavian racers AXA-Adidas.
"These teams will be looking to conquer the notoriously difficult Kiwi terrain and also the Kiwis themselves," Mr Bates said.
"We have announced significant prizemoney this year and a world championship spot is up for grabs, so it promises to be a compelling battle at the front of the field."
There were only "a handful" of slots remaining for the March race and Mr Bates encouraged teams to enter soon to avoid disappointment.