how late in the season can you leave your boat in??

Hey there!

So this is my first year owning my own boat. I bought a 2001 X-Star back in the spring. In the past, I've always used my dad's boat, and he's always put the boat away on Thanksgiving weekend. Keep in mind that I live near Toronto, and Thanksgiving here is usually somewhere around October 8th to October 12th. I would say that the average temperature here in Toronto in October is somewhere around 9C-14C (48F to 57F) degrees. There is always a risk that the temperature could touch the freezing mark, or even slightly below, towards the end of October as well.

So my question is... how late in the season can you leave your boat in? I'd like to leave it in for the entire month of October and get a few extra weekends of boating in. Also, my boat has a very minor leak in it, so sometimes there's a tiny bit of water in the bottom of the hull. So with that being said, I'm assuming it would be better to take the boat out of the water during the week and just pop it in on weekends!?!?!?! Or should I just play it safe and winterize on Thanksgiving weekend?