Now I wonder if there are any events for the occupation of Canada by the Combined Syndicates?
Yes, there are. Fist of all, when the CSA starts occupying important Canadian provinces the King has the opportunity to flee the country. When (almost) every Canadian provinces with VPs is under your control, Canada should capitulate and you will have the opportunity to create a puppet Canada and/or a puppet Quebec. If you are allied with the Commune of France, they may be interested in Quebec.