If you missed the opportunity to do the Amtrak Autumn Express this year, there is another way, which you could combine with a weekend in Montreal. I regretted the fact that we won’t be able to do the Amtrak Autumn Express, but I remembered Barney’s Version in which Paul Giamatti as the lead character takes Amtrak from Montreal to New York City. This happens to be one of the best way to see the autumn foliage without having to drive 6 to 8 hours.
Amtrak charges $146 for a round trip ticket from NYP to MTR. The trip takes almost 11 hours on the way To Canada and 10 hours and 30 minutes on the way back. If you plan your long weekend in Quebec with enough time, you might be able to find a cost effective airfare for your return, in case 10+ hours on a train is too much for you.