I once read an anthologized article by a Quebec PoliSci prof, a sovereigntist who visited Alberta in the early 80s to compare Alberta separatists to the Quebec version. He found that the Albertans, unlike the Quebeckers, had little sense of a positive cultural identity, and were basically just coasting on grievances surrounding federal energy policy.
That same anthology also contained a description of Nick Taylor, the legendary Alberta Liberal leader, speaking on a panel at a separatist rally, and telling the assembled rowdies that they were being used as pawns by Peter Lougheed in his battles with the federal government. Which was probably a pretty accurate description of the situation.
As for hard stats, the Western Canada Concept party won a by-election in 1982, and after a brief season of euphoric anticipation, were completely shut out of the legislature in the subsequent election, winning even less of the popular vote than the NDP. This at the height of western alienation and anti-Ottawa sentiment.
Long and the short, no, I don't think there was ever a serious possibility of Alberta separating. You'd need SEVERELY worsened relations with the federal government than in OTL. As I recall, even the federal Liberals weren't defending the NEP by the time Mulroney shut it down.