I'm going to be driving from Hartford to Montreal in June. According to Google Maps there are two possible routes: the 87 via Albany, NY or the 91/89 through Vermont. Both routes take about the same amount of time. What scenery can I expect along each route?
It's a matter of preference, the Vermont route is a little bit faster, though a little plain in my opinion. I prefer the NY route because the scenery varies, you get to see mountains (Adirondacks) and lakes, the road isn't just a straight stretch and there are plenty of rest areas and service stops. The 87 becomes the 15 in Quebec which is a highway. Those have higher maximum speed limits than regular provincial roads and I'm a little embarrassed to say, maintained more regularly.
Also, and this is entirely subjective, it's my impression that the crossing at the NY border is more efficient.
I'll answer for the Québec part of it since I'm a local: The 15 will be much quicker but route 133 which we call Route des Patriotes here is very nice and you could take it up to Saint-Jean-sur-Richelieu if coming from Vermont.
And try not to get to Montreal at traffic hour, it can take quite a while to get on the island.