Hopkins, who played the part of Gamling in LOTR, will start the track at Cape Reinga on October 14. He'll document the trail with weekly podcasts, the first interview will be of his 9-year-old grandson asking Hopkins questions.
The first night Hopkins will camp in Twilight bay, 12km from Cape Reinga, as it's where he and his father moored their boat when they were commercial crayfishermen in the 1970s. Then he will cover between 15km and 30km each day.
As a grandparent to three Hopkins empathised with the charity Grandparents Raising Grandchildren. He wants to raise $50,000 to take some of the financial strain off the affected families.
"To suddenly become a full-time parent again is financially and emotionally hard. Many of them are there through very traumatic circumstances
"One person had to go to the school to pick up their grandchildren and figure out how to tell them mum was dead because dad had killed her. Or because mum and dad are crackheads on P, they've lost the plot. Or the levels of violence people know they have to get kids out of there.
"Grandparents Raising Grandchildren is about being a resource there for these people to contact and seek assistance."
Ironically tramping is not Hopkins' forte - he only did his first one two weeks ago when he joined the Auckland Tramping Club on an outing. To prepare for the arduous trek he's been donning a backpack with 16kg weights inside and "tramping" around the city.
"On the weekend I did a six-hour walk around the city with a backpack on.
"Bella Vista Reserve has 120 steps. I'll just go up and down there for an hour."
Hopkins has worked as a professional dancer, theatre company actor, television and film actor, voice actor, and radio host over his career.
Grandparents Raising Grandchildren provides support to over 7000 grandparents and caregivers who care for more than 12,000 children across New Zealand, a figure that has nearly doubled over the past 10 years.
To donate click here. And visit Hopkins' Facebook page to keep up to date with his progress.
Te Araroa
The idea was first floated in the 1970s when it was advocated for by the Federated Mountain Clubs of NZ and in 1975 the New Zealand Walkways Commission was established.
But it wasn't until journalist Geoff Chapple picked up the idea in 1994 that it got some traction. He founded the Te Araroa Trust and the route was officially opened in 2011 after 10 years of work by hundreds of volunteers.
The trail has approximately 300 sections ranging from walks of one to two hours through to an approximately nine-day route in the South Island where most trampers haul large amounts of food and gear. Forty per cent of the trail crosses conservation land.
Last year it is estimated that 550 people did the whole trail over the summer.