I would tell you that I don't agree with either of the points in your question, quite frankly. On the question of one or two engines, even going back to when we selected the F-18, which is a two-engine aircraft, that wasn't a mandatory requirement of the replacement.
In fact, since 1991, U.S. aircraft have not lost a single-engine fighter to an engine failure. That's why the 777 that flies you from Vancouver to Sydney only has two engines, whereas the 747 had four. The reliability of engine technology has increased to the point where there is really no requirement to concede to have two. Technology has improved. There are some advantages to having a single engine. One is maintenance costs. Engines are a huge part of that. So on that question, I don't know the background of the individual you were speaking to.
The second part of it is that in fact aircraft tend to work better in cold temperatures. They're more efficient in cold temperatures, so there's nothing precluding a single- or a twin-engine aircraft from operating anywhere in Canadian airspace.