In the new new economy, people can leave the big city and live rurally if they have a good internet connection. It helps to have a good air connection too. On PEI where I used to live, it took 15 minutes for people who lived near Chatlottetown to get the airport. The 6am flight to Montreal meant that you could be in Washington, New York or Toronto by 10am. You could hop to Halifax and be on the evening flight to Europe.
Now for the Estrie, Montreal YUL is close - an hour 30 minutes if there are no accidents on the 20. But an early morning flight means a 3am wake up. If you live in Sherbrooke you have another hour.
Bromont airport can take a 737. It is 30 minutes from most of the Estrie. An hour clear from Sherborooke. What might be the appeal if say Porter had a daily morning and an evening flight to Toronto? I suspect that the flights would be full right now. And what would this mean for the Estrie? I think that more and more people would consider moving here from Montreal. In time there would be enough demand to offer a weekly New York Flight on Mondays - maybe a weekly Icelandair flight on Fridays to Europe?