Mr Cleworth and his wife Michelle have a family of eight boys, five of whom were recently enrolled at Tarras' tiny sole-charge school, after their father was appointed its new caretaker.
The family's arrival pushed the school's roll up to 25, just one pupil short of the required 26 to qualify for two fully-funded teachers.
At present, the school has Ministry of Education funding for 1.4 teachers and community fundraising covers the balance of the second teacher's salary.
Today, Tarras will have something to celebrate when two more boys from a Cromwell family start at the school, boosting the roll to the number of pupils required for additional funding, with "one for safety", elated principal Noelene Pullar said.
"When the 26th little child walks through that gate we get a whole new funding formula and this school has been looking to that for a while."
After dropping from a two-teacher school in about 2000 because of a declining roll, it had been "11 years building it up again".
For the 10-strong Cleworth clan, shifting to Tarras was an easy decision.
The "well-travelled family" has moved from place to place in their two-storey mobile home for about a decade, apart from a stint in Tuatapere where they settled for a couple of years.
"It wasn't the right place, so we went back on the road," Mrs Cleworth said.
Most recently, they were living near Lake Dunstan, so the two oldest sons could work at a local vineyard.
Then, as the family was relocating to Blenheim, a friend phoned with news of the caretaker opportunity in Tarras, where the boys had earlier enjoyed attending school for a few weeks.
"We were sort of always wanting to find that little place, that little piece of paradise, so we could raise our boys," Mrs Cleworth said.
"We want them to be together because they've always been together.
"We're quite a tight family.
"It's taken us many years to find a place like [Tarras]."
The boys have mostly been home-schooled until now and had "come alive again" since being at Tarras and having regular playmates, Mrs Cleworth said.
The entire family has been in Tarras for more than a month, but only just moved out of their mobile home into the school house after getting furnishings for their new fixed abode, where they plan to stay put, permanently.
Mr Cleworth, a former truck driver and scaffolder, loved his new job and highly rated his employer, Mrs Pullar, who was "the best boss I've ever had".
After injuring his back in a scaffolding accident, Mr Cleworth is on a sickness benefit, which is supplemented by his 10 hours a week caretaking.
However, "it's not the money, it's family. Family's first", he said of their new life in Tarras.
The school had about eight responses to its caretaker advertisement, which had listed children as "an advantage" for prospective applicants, Mrs Pullar said. Mr Cleworth's handyman skills and unusually large brood made him an obvious choice.
"We just couldn't believe our good fortune really.
"I mean, eight boys, it's almost unheard of these days, and probably the lovely thing about it is they're very very good students.
"And our school grounds are looking wonderful," Mrs Pullar said.
