They calculated that to get to Eden Park on time, they would have to travel around 500km a week, through mountains and snow.
It is a journey that has seen them attacked by bears in Romania, crippled by frostbite in China, and surprised by their encounters with out-of-the-way rugby clubs.
"We wondered whether rugby ... has spread across the world. And we've been pleased to draw an unbroken line of 28 countries which have a rugby community and culture - even if it's a handful of clubs."
Followers of the oval-ball code have sprung up in Azerbaijan, Iran and Slovakia. But Mr Hudson said the biggest surprise was the hugely passionate rugby community in Pakistan.
"You imagine your Pakistani and Indian guys to be cricketers, quite lean, but you're talking about 6000 players registered there."
A keen rugby player himself, he said he may have to consider a new position on the field after shedding 25kg while on the road. The pair have lived on $10 of food a day, snacking on dry pasta, tins of tuna and pot noodles.
They plan to attend several World Cup pool games on their way to the final.
Their trip is raising funds for the charity Tag Rugby Trust, and the two are also seeking New Zealand clubs to "buddy up" with clubs in poorer countries.
But will they cycle back home? "Absolutely not," said Mr Hudson. "We're here to stay. I've lost all my muscle, toning, my strength. I can barely do anything apart from cycle. It's not cardio, it's attrition."
ON THE WEB
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