Wintonick was recently diagnosed with a rare form of liver cancer and had been admitted into palliative care late last week.
A self-proclaimed film festival addict, Wintonick's career spanned decades and took him all over the world.
"He was constantly travelling to film festivals, introducing people around — pretty much everybody in the documentary circles knew Peter," said Mila Aung-Thwin, chair of the Montreal International Documentary Festival and co-founder of production company EyeSteelFilm.
The Ontario-born, Montreal-based Wintonick was best known for the 1992 documentary Manufacturing Consent: Noam Chomsky and the Media, which he co-produced.
The film took home awards from festivals around the globe and, according to the National Film Board, remains one of the most commercially successful documentaries in Canadian history.
In 2006, Wintonick won the Governor General's Award in Visual and Media Arts. He is also one of the founders of DocAgora, a filmmaker collective that focuses on cutting-edge, digital documentary production and new ways of funding filmmakers.
In Montreal, where the International Documentary Festival continues this week, filmmakers remembered Wintonick as a man devoted to his craft and one constantly pushing the medium forward.
Yesterday afternoon, friends and admirers of Wintonick's work gathered at the festival for a screening of PilgrIMAGE, a 2009 movie about filmmaking that he co-directed with his daughter, Mira.
Investment in the next generation was one of Wintonick's defining characteristics, said Aung-Thwin,
"His presence is felt on thousands of films in very concrete ways," he said, adding that his own early career was shaped by Wintonick's guidance after he landed an internship with the filmmaker.
Wintonick's health declined sharply in recent weeks, but he was still eager to see old friends, many of whom were in town recently for the annual doc festival.
"Peter, I think from the initial diagnosis, had been remarkably Zen," Aung-Thwin said.
"He would say things, when people would come to visit him at his home, like: 'If you have any tears, just collect them in a cup and pour them in a plant or something. I don't need them. Just come here and have fun, and hang out and tell stories.'"