It's very difficult to know. Weirdly, while the CIA released a lot of the data about général MKULTRA, no data about the Montréal operations were released. There are certainly even more facets to the program we don't know about.
If you wanted to know, the CIA decided in 1973 to burn all documents about MKULTRA, fearing Watergate would lead to the Church Committee. One cache of documents had been incorrectly stored, which later came to light giving us all we are certain of about the project.
Oh, the Duplessis Orphans are a completely separate and just as tragic catastrophe of Quebec history :(
That said, yes we do actually know about the MKULTRA Montreal Programme, because of testimonies. We just don't know what more there was, and there is certainly more.