So I've been trying for the last two years to break through a brick wall for my 2nd-great grandfather, Edward McDermott. I knew he came from Ottawa, and two days ago, thanks to the good folks here, I broke through with an 1851 census listing him, his brother Hugh, and parents Michael and Catherine. Thing is though, it listed his brother Hugh as having been born in Quebec first, in 1848, and Edward Patrick in 1850. So working backwards, Hugh was found in a baptism record at Notre-Dame de Quebec on 13 Aug 1848, and before that, a marriage between a Michael McDermott and Catherine Connell at the same church on 21 Sept 1847.
The 1851 census said Edward was from County Leitrim, and Catherine from Kings County (now Offaly). The marriage record noted that Catherine's parents were 'of Quebec' but it still basically all jives with what I know about Edward Patrick and seems to make sense. Much later on he would answer on censuses that his mother was Irish, Canadian, or Irish-Canadian so I figure maybe her parents were from Offaly but she was born there.
Now the questions:
I know next to nothing about Quebec records because this is all such a recent development, but first, do these all seem like reasonable assumptions? Is there a big trove of local records I've missed and should look through?
And if Michael was a recent immigrant, which seems likely, does it make sense that he came through Grosse Ile? A look at the records there only turned up one Michael McDermott who lived, and he arrived a few weeks before the marriage. A summary of that record is here, and suggests that he may have been one of the Strokestown 1490. Searching online seems to suggest significant research may have been done on these families, but I'm not turning up anything for Michael (or McDermotts who emigrated in this group at all). Is there something I'm missing or somewhere I should go for further research about him if he came through Grosse Ile?
And lastly, is there any other way I can more conclusively connect Michael at Grosse Ile -> the marriage record -> the census of 1851? I'm not sure what land / church / other records may still be floating around.
I appreciate any help you're able to give - thank you.
(Also, I'm trying to get the wikitree profiles updated. I've added photos and links where possible, and provided the rest here. Please let me know if you need any others.)