The couple leave England every year in November, spend two weeks in Malaysia and then four or five months in New Zealand.
They have a lifestyle block in Kawhia, Waikato, but spend a lot of their time driving around the South Island in their Toyota Hiace campervan because they like the freedom of camping.
They bought the Hiace in 1997 with 30,000km on the clock and it has now done 370,000km.
"We like the open space. We prefer the South Island to the North Island," Mr Head said.
They first visited New Zealand in 1989, on the recommendation of Ms Mitchell's nephew, and have come every year since.
Their favourite spot is Queenstown and they have become firm friends with Creeksyde owner Erna Spijkerbosch.
Mr Head said he had noticed the "stress levels" in New Zealand skyrocket over the past 20 years.
"People are driving faster and more dangerously. Property prices have increased considerably. When we first started coming to Queenstown there were very few developments," he said.
His favourite activity in Queenstown is picking redcurrants and walnuts at Creeksyde and wild raspberries at Skippers Rd.
"Creeksyde is very green.It's always tidy and hygienically clean. Many camp sites are getting very poor," he said.
New Zealand camp sites were among the best in the world, he said.
"New Zealand is better prepared for tourists than anywhere else. The camp sites have all the facilities. Kitchens with utensils, showers, toilets, laundries. It's ideal," he said.
On his travels, Mr Head has visited every brewery in New Zealand and has compiled a book on New Zealand beers and breweries.
He also supplied all the New Zealand native plant species for the Eden Project, a visitor attraction in the United Kingdom.
The site has the world's largest greenhouse and inside the artificial biomes are plants collected from all around the world.
