Doesn't answer your question, but may fillin a few holes. In the parish records for St-Hyacinthe.Burial of Marie Louise Phylemine Klebour, daughter of Jean-Baptiste Klebour and his wife, Magdeleine Schmeltz, in 1846.
Baptism of son, Dominique Victor, in 1848 and Lucien Victor Lafontaine in 1849.
The reason he was married in the US is likely because it was less likely to be discovered that he was already married.
He and his first wife are in St. Hyacinthe in the 1851/52 Canadian Census, with children, Emil, aged 13, born in New York, Victor, aged 3, born St. Hyacinthe, and M. Amanda, aged 1, born St. Hyacinthe.