De Grandmaison was born in Southern Russia, and after a tumultuous upbringing ending with being a prisoner of war, he decided to flee Russia and escaped to England. Friends helped him attend St. John's Wood School of Art in London and afterward, urged him to immigrate to Canada. He settled in Winnipeg in 1923 working in a commercial art firm, as well as joining the Winnipeg Arts Club. He painted portraits in Winnipeg and visited First Nations settlements to paint, then traveled to Saskatchewan where he painted more First Nations portraits, at last settling in Alberta, in Banff. From 1925 on, he preferred to record his portraits in pastel because they were portable and easier to obtain than oils in Canada at that time.

On September 19, 1931, he married Sonia Dournovo, a fellow Russian artist living in Canada. Nicholas and Sonia decided to settle in Calgary, where they made their living painting portraits of children. But soon they both became interested in characterization, which developed into a lifelong study of the First Nations in Canada and America. They started to travel more to various reserves and reservations across North America in order for Nicholas to paint, but in 1939 made their home in Banff.