The Flying Welshman has given you links to some good data for you to analyse. I think the data will tell you that starting a trip like this in early October would not be wise. The season here is fantastic but short. I think you said you were thinking of starting from Lion's Head. I'm at Lion's Head Marina and we haul out on Thanksgiving (Thanksgiving is in mid October in Canada). The weather can be very nice in September with some of the best sailing of the year but it can also turn quickly once you're past mid month. There won't be nearly as many recreational sailors out on the water in October as in the summer to help you with VHF transmission relays if necessary or help you out of a jam if the weather turns bad quickly.
It's a noble cause but I think you would be better doing this in the summer.
My humble opinion.
Georgian Bay, Ontario
Catalina 34 - "Good Idea"