Such aspirations would be a tad overreaching, if expressed as the aspirations of "Canada" per se. Few enough were the Canadian aspirations, at this point in history, which envisioned a Canadian nation stretching from Nova Scotia to British Columbia. And these, for the most part, as aspirations on the behalf of Britain's lands, rather than aspirations on behalf of a Canadian union which did not yet exist. No, more so, the Alaska purchase must be regarded as a wake-up call to those who aspired towards a transcontinental claim for British North America, whose best expression would be the Canadian union. The Canadas had after all been at war with the United States, within living memory, at this point. And the Canadian union was the effect, at any rate. See this text, for a good summary of the issue.

There was a question three days ago that offered me a chance to talk about British Columbia's reaction to the Alaska Purchase. It might be what you're after.