Fly to Quebec City
You can easily fly into Quebec City from anywhere in the world. Prices are often reasonable and you avoid the hassle of taking the bus from Montreal to Quebec City.
Quebec City Jean Lesage International Airport has direct connections to most major North American hubs including Chicago, Montreal, Toronto, Philadelphia, and New York. You will likely stop over in one of these cities on your way to Quebec City.
Both Star Alliance oneworld and SkyTeam let you reserve your entire flight with a single airline, even if you will be flying with a different carrier for a leg of your trip.
In summer and fall, Air Transat flies directly from France to Quebec City*. Porter Airlines offers flights to Quebec City from twenty cities in Canada and the U.S. with a layover in Toronto.
Air France offers ground transportation to Quebec City from Montreal airport for its passengers.
Always compare prices, routes, and flight times before making a reservation. Here are a few helpful websites:
*In summer 2017, this direct link is cancelled due to construction work at Quebec City Jean-Lesage International Airport. This service is therefore offered with a transit in Montreal during this period.