In looking at the line further - Guillaume Audesse (married Archange Couture) was the only known child of John William Awdas and Sarah.
John/Jean Odesse, Guillaume's half brother, was born 20.AUG.1829 in Quebec, the son of John W Audas and Marguerite Noel. The other child of John and Marg. was Thomas Odesse (born 16.OCT.1827 and died 3.DEC.1927 - yep, he was 100 yrs. old).
In looking at Yorkshire records further, I believe that the wife of John William Awdas was a Sarah SCHOLES (married in Snaith, YKS on 13.FEB.1809). John William was born 30.MAR.1789 the son of John Awdas and Jane Garret.
So, Guillaume/William had two half brothers.
There are quite a few Awdas families that appear in Yoprkshire on the so-called "non-conformist rolls", lists of people who refused to convert to the Church of England; they are frequently referred to as "popish" and many were arrested and fined.
Considering that both of Guillaume's half brothers were baptized Catholic and John William was married Catholic to M. Noel, I strongly suspect that they were Catholics living in Yorkshire who fled to Canada, specifically a Catholic province of Canada - they were still under Brittish rule, but could practice their religion in peace.