i'm not from canada but i'm from the buffalo/niagara falls new york area and when i was younger my family drove down every year mid november and were gone for a total of 2 weeks.
we have taken all 3 major routes.
we never ran into bad weather on the way down but have SOMETIMES on the way back.
the worst was probably 2002.
it started snowing heavily at the new york state line and took us 5hrs to get home when it should have take 1.5-2hrs.