"My understanding is that many of the people coming for the Rugby World Cup will be travelling independently using camper vans."
While Harford said this was good news for camper van and rental car companies, it could limit the benefits of the tournament to the hotel industry.
The industry is trying to pull some of the traditional seasonal tour group market back by letting them know beds are available except in certain locations during key games.
"We will lose some, but I think the real gains will come after the Rugby World Cup. A lot of people will be waiting until it is over to come here."
Former Te Puia chief executive Graeme Osborne, of The New Zealand Company, described the drop in international arrivals to New Zealand as significant, pointing to the same factors as Harford.
"During the Rugby World Cup, accommodation will be at a premium and prices will be unattractive to your normal tourist."
But he said pre-tournament months were suffering because many people had deferred travel to come here during the tournament.
Holiday Accommodation Parks New Zealand Rotorua president Dave Adams, of Rotorua Top 10 Holiday Park, said holiday park bookings during the tournament were firming up, but operators expected a lot of walk-in or late bookings.
"There will be a lot of free and independent travellers who are aware that there is a reasonable amount of accommodation outside games and they will book closer to the time."
As in May, holiday parks was the only accommodation sector to record growth during June and Adams said things were also looking positive for July and August.