Do be aware that many campgrounds close right around Columbus Day in New England. Also be aware that Columbus Day weekend itself is the very peak of leaf peeper season--not necessarily the peak of the foliage at any given location, though it probably will be somewhere, but the peak of the people coming to look at it, and hence reservations are very strongly recommended for that weekend at the least.
Coming and/or going across through Ontario is pretty and generally not overly traffic-laden (particularly when compared with I-90), but it sometimes does seem to go on forever. Obviously you do have to be properly prepared for the border formalities.
What sorts of things are you intersted in seeing and doing along the way? Nature, hiking (strenuous or gentle), museums, wineries, athletics, cities, antique stores, touristy kitsch....? Similarly, how comfortable are you with roads that are not especially flat or straight or wide?