We spent two nights and ate four meals at this tiny inn (5 guest rooms, I think). Mt. Megantic (near the hamlet of Notre Dame de Bois) is in the southeast corner of the eastern townships, just a few miles north of the maine/new hampshire border and 30 mi from Coburn Gore - dramatic, beautiful country, with sweeping vistas and VERY few people.
The inn specializes in very reasonable packages (lots of weekenders from Montreal) including 5 or 6 -course gastronomic dinners, with produce, herbs and fruits from their lovely kitchen garden and use of fresh provender from local farms (ducks, chickens, elk, foie gras, cheese, trout, etc etc). Artisanal or small farm agriculture is a big deal in Estrie, and they take full advantage of it.
While not on the absolute top level (like the Auberge Hatley, one of our other stops, we appreciated the artistry and care of the chef - the cuisine was delicate, tasty and of very high quality, with a personal touch, including creative uses of flowers from their garden (a daylily blossom holding cheese topped a generous salad; a rugosa rose blossom was served with a chocolate dessert and we were strongly urged to eat the perfumy petals along with the chocolate - the combo was indeed delicious.
Some highlights were a carrot soup garnished with fresh chervil and tarragon, elk with a classic venison sauce, tender and rare,and a full flavored duck breast . Breakfasts were also excellent and carefully cooked - rather than overly sweet muffin-oid b&b fare, we were offered beautifully cooked crepes on one day and a velvety, savory "pancake/omelet" including corn, and tiny cuts of herbs and vegetable, perhaps inspired by the proprietors' years of residence in Costa Rica, on the other, along with homemade bread and jams.
The adjoining national park offers "astronomy evenings" (there is a major observatory situated on a mountaintop there) as well as remarkable views from atop Mt. St. Joseph. I highly recommend a visit to the inn and this remote, lovely area if you can work it into a trip to quebec province.