And now his wife of 11 years, Stacey, along with "The Mighty Quinn Collective", is organising a massive fundraiser in Hāwea coinciding with his birthday.
Proceeds of the event will go to child health research charity Cure Kids.
Mr McIntyre, 42, attended Southland Boys’ High School and then the University of Otago before initially working for Queenstown Lakes District Council-controlled organisation CivicCorp, as an enforcement officer, straight after graduating.
He and his wife then lived in Brisbane, Australia, before returning to the Central Lakes, where he worked again for the council, ultimately becoming resource consents manager.
Four years ago, he set up environmental consultancy firm Enviroscope, based in Wānaka.
The rugby player and father of Zac, 14, and Ivy, 10, had played about eight minutes for Invercargill’s Waikiwi Rugby Club’s 125th jubilee on May 18, his third game in about a month.
Mrs McIntyre, 40, said her husband had started training again, was fit and healthy and "just on that rugby buzz, and having a great time with his mates".
That night, he ended up at Invercargill’s Northern Tavern. About 9.25am the following day, his body was found by a close friend near the intersection of Sydney and St Andrew Sts.
His death was not suspicious and the case was referred to the coroner.
Mrs McIntyre said her husband’s death was a "medical mystery" because he had a "negative autopsy".
"Which means, basically, he was just a beautiful, healthy man on paper — they could not find any medical reason why he died.
"He had no symptoms, he had no medical history ... he didn’t have a heart attack ... he had no disease."
Mrs McIntyre, a nurse of 20 years, said that she believed his death was caused by an electrical malfunction in his heart, known as an arrhythmia.
She subsequently had all his immediate relatives tested. His dad, Brent, has since been diagnosed with long QT syndrome, which can be hereditary, while daughter Ivy has Wolff-Parkinson-White syndrome, which is congenital.
Both can be fatal.
"Unfortunately for Quinn, he probably did have something like that underlying, and the first time it ever manifested, it resulted in death," she said.
"That’s the scary thing for me, the first warning that you have something like this going on is death, that is the only symptom."
Along with playing rugby most of his life, Mr McIntyre was also a talented rower and "pushed his body to the max".
"It just happened in the worst possible place, at the worst time, as he’s outside, by himself.
"Had it happened inside the pub, we may have had a different story on our hands, because there would have been a defibrillator inside, and that’s what you need."
Mr McIntyre’s death has since been referred to Auckland’s Cardiac Inherited Disease Group, which comprises a team of specialist doctors and researchers — and his family are now on its register, and will be followed and tested.
Mrs McIntyre said her husband’s father’s condition could be managed with medication.
And while Wolff-Parkinson-White syndrome, an extra electrical pathway between the top and bottom of the heart which could cause the electricity to get out of sync, could be "100% cured", in Ivy’s case, that was not possible because hers was in "the power station" of the heart.
"It was really deflating to be told, ‘we’re sorry, we can’t cure it. She has to live with it now’.
"So we send Ivy to playdates with a defibrillator. That’s her life."
Mrs McIntyre said every day was tough, but the "milestones" were particularly difficult.
That was why they decided to reboot "Quinnchella", a music-themed festival she threw for his 40th birthday, to make one of the milestones a celebration.
The January 25 event, being held at the Hāwea Hotel, aims to raise at least $40,000 for Cure Kids. That money will be ring-fenced for a research project into early detection and intervention for cardiac arrhythmia and inherited cardiac conditions.
The lineup includes Canterbury band, Pieces of Molly, Melbourne’s Matt Joe Gow, fellow Australian Levi Smith, Mr McIntyre’s cousin, known for his band Loose Bricks, Southland’s Lachie Hayes, who has just released a new single, and Flat Out, a band comprising four of Mr McIntyre’s mates.
Mrs McIntyre said she had been "blown away" by people’s generosity.
"I think it’s also because Quinn was good too.
"He was such a larger-than-life character."
Meantime, Zac and his sister Ivy were proving "incredibly resilient" — "it’s bloody hard".
"He was such a good dad — they just adored their father.
"I know he’s left an incredible mark on his children, but I just am so sad for all those other things that they’re going to miss out on.
"Ivy loves Lego, and she’s building a wee Lego creation and she looks up and goes, ‘Mum, you know when you get married ... you know how your dad walks you down the aisle ... who’s going to walk me now that Daddy can’t?’
"It’s put them on a different pathway now that they just don’t deserve to be on at such a young age.
"But they blow me away constantly. They are my rocks and they inspire me to keep doing what I’m doing every day."
Tickets for Quinnchella cost from $120, with transport add-ons, via quinnchella.curekids.org.nz. The event includes an auction, for which items are being sought; offers can be made by emailing quinnchella25@gmail.com.
