The team has been based on a farm not far from the Kentucky Equestrian Park, but move in to their official stables today.
Endurance chef d'equipe Madonna Harris says it will be a testing race, although she has every confidence in her trio of riders.
The World Championships are the only four-star endurance event in the world. It will be the first time at this level for the Kiwis, and for many other combinations.
"Of all the disciplines, this really is the toughest," she says. "Throughout the race we present to the vets seven times."
And at any time, if the horse's heartbeat doesn't come down fast enough or there is a niggle of any sort, a combination can be pulled from the race. With just three in the New Zealand team, there is no room for error, with no chance of any team accomplishment if all don't finish the race.
The input of those supporting the riders is just as important as those on the horses.
"Our grooms have to be particularly adaptable and malleable to ensure we get through this," says Harris. "After looking at the layout of the course and the vet gates, we've had to make a few changes to our strategies and learn some new techniques."
The heat will be another big challenge for the endurance competitors, as will the mass start.
About 130 combinations are expected on the start line. Anxiety levels will be fever-pitch and that half hour before the race, and half hour into the race, can be make or break.
There is also the tactics of the other teams to contend with, which, according to US team rider Meg Sleeper includes the actions of the UAE (United Arab Emirates) riders, who gallop past screaming to unsettle the other horses. The US team has been practicing these moves in order to get their horses used to it, Sleeper said.
"Everyone is wired," says Harris. "There are flags, banners and general mayhem going on - our riders just need to find an area and remain calm."
Combinations will do six loops of varying distances throughout the race - the shortest is 18km, and the longest 39.9km.
The Kiwi horses left New Zealand late August and have now acclimatised well. Harris says each is in peak condition and now ready to race. In recent days they've had plenty of attention, including New Zealand team equine physiotherapist Nikki Lourie.
Harris is picking a Spanish combination to take the individual and perhaps United Arab Emirates for the team.
"But I am very confident about the quality of our own horses and our ability to ride at speed ... we just need that bit of luck to go our way."