Okay, so you got Sponsor Approval in October? You probably have a little way to go. Not hearing anything at this point is normal. You have to sit on your hands and wait
Ottawa's published time is 13 months for 80% of applications. If they're requesting documents, it sounds like they have begun to process you already, which is great.
It *seems* lately that Ottawa has been getting Americans done in 7-8 months if there are no complications, but that's my observation not fact. Anytime they request additional documents, it usually delays the application by a month or two, but not always.
Really, there are no rules for how Ottawa does things. For every case, there's an exception out there........ it keeps us on our toes.