The outdoors is spectacular - particularly if you like the ocean, and there are a ton of small museums, plus if you travel towards the end of your window you get the fall colours.
In addition to Vancouver Island, I'd perhaps consider the Canadian Maritimes. (I'm planning a trip there myself in the fall.) The outdoors is spectacular - particularly if you like the ocean, and there are a ton of small museums, plus if you travel towards the end of your window you get the fall colours.