"Sevens is a pretty fickle game," New Zealand coach Gordon Tietjens said. "You look at that pool, we've got to get up for all of those games. It's going to be tough going to Vegas."
New Zealand's victory in Wellington, sealed with a 27-21 triumph over England in the final, helped them move to second in the overall standings behind South Africa.
Finishing inside the top four this season is vital as it provides direct entry to next year's Rio Olympics where sevens will make its debut.
"We'd love to win the series and we've got to continue from here," Tietjens said after Saturday's final. "We know the next tournament will be really tough."
After playing in the US, the series takes a short break before tournaments in Hong Kong and Japan in late March and early April respectively. The nine-leg circuit wraps up in May with the final events in Scotland and England.
New Zealand's win in Wellington was perhaps the most impressive of their eight titles in the capital given they were forced to play with so many youngsters.
They lost veteran Tim Mikkelson in the build-up with a groin injury, while skipper DJ Forbes missed the 17-7 semifinal win over South Africa and the final because of a foot complaint.
"It would be probably one of the highlights of my career," Tietjens said of the victory.
With their experienced players on the shelf, New Zealand were led by Joe Webber, Scott Curry and Sam Dickson, while debutant Rieko Ioane was superb. The 17-year-old bagged two tries in the final after he needed a dispensation to play.
Ioane looks a player of true talent and Tietjens said he would like to have him at his disposal for the rest of the series.