CAPP's June 2016 "Crude Oil Forecast, Markets and Transportation", puts Canadian crude oil supply (includes crude oil production + imports of diluents) from Western Canada at 5.45 million barrels per day (Mb/d) in 2030. Table 4.1 of the same report shows the capacity of existing and proposed "major" pipelines exiting the WCSB. If Kinder Morgan Trans Mountain, Enbridge Line 3 and TransCanada Keystone XL are built, that capacity will reach 5,812 Mb/d. Energy East would add another 1,100 Mb/d, for a total of 6,912 Mb/d. 
Refineries in Ontario and Quebec have already access to Western Canada and U.S. crude. The Irving refinery, the largest in Canada, has switched back importing crude from foreign countries, providing easy to refine conventional light crude oil at a competitive price. 
Foreign markets other than the U.S. for Western Canadian heavy crude oil are practically inexistent at around 25,000 b/d, or 0.8%  of total production (NEB: "2015 Oil Exports and Imports Summary")