I agree with brickster about west of Sundre. You could also go down to Crowsnest Pass (long drive for you I know) ther are tons of trails down there too, just go to a gas station and ask for the Quadsquad map.
Just getting back into biking, used to live/ride in the wiaprouse burnt timber area but I have heard lots of it closed now etc. Have friends that go out to the invermere valley and some really good riding out there and the season starts early in mid march. Suppose we will start at Indian Graves Maclean creek etc once they open for around here. Have to take it easy for a bit as its been a bit for me, and my wife is new to the sport!