Are you certain the Patrick buried at Colgan is yours? There is also a headstone which says Mary McCann died 1866, w/o Patrick.
Here are the McCanns on 1881 census. Names are the same as supplied by Robert. Aldfield Pontiac Quebec
McCANN Patrick, 59, Ireland, farmer Mary Ann, 29, Ont Mary, 30, Ont JOhn, 26, Quebec Patrick, 24 James, 23 Nicholas, 20 Michael, 19 Edward, 17 Daniel, 12 Marguerite Jane, 10 Esther Ann, 8 Joseph,6 David, 3 Theresa, 7/12, b 6 August
Census indicates that Patrick and Mary Ann, aged 29, are married. All RC. From John down, all born Quebec.
1891 census Aldfield Pontiac Quebec
McCann Mary, 45, widow, Daniel, 21 Ester, 17 Margaret, 14 David, 12 Dennis, 7 James, 5 All born Quebec.
From Druoin Collection Michael McCann, son of Patrick McCann and Mary Murphy, married Mary Kearn, 26 May 1886 St Cecile De Masham. Some one has put a correction in and changed Michael to Nicholas with explanation that priest put wrong name in heading and right name in entry.