Honestly, hiking and farmers markets are the only Vermont-y activities I do in the fall. Even sticking to that will give you a decent sense of what people do here.

Edit:

I do have one place you have to go, though! Yates Family Orchard in Hinesburg (?) sells something called the Dreemee, which is a maple cremee (what the rest of the country knows as soft-serve) on top of a super fresh cider donut. You can upgrade to the Supremee by adding apple pie filling and caramel sauce. It's mind-blowing.