We don't form a view in the way you describe. In fact, the Canadian dollar is most correlated with the price of oil because of the importance of oil in the economy. When the price of oil was around $100, the Canadian dollar was in the nineties—actually around a hundred cents.
We have models that try to capture the historical relationship between oil and the dollar. The dollar does have some other things to it. Not just oil, but other commodities matter, and the interest rate differential between Canada and the U.S. matters. But that's about it. It's a pretty simple model of how the exchange rate is determined.
In real life, everything that moves affects the market's estimate of what interest rates will be some day, because it interacts with what inflation will be. That means that anything that moves can affect the dollar, because it changes that expectation.
In economists' models, really, anything that moves in the model, the exchange rate reacts to. It makes it very hard to ever form a view of what the appropriate level is. It all depends on the forces acting on the economy at the time.
There simply is no hard and fast rule. As I said earlier, that's exactly why we have and why we need a flexible exchange rate. We can't be forcing it to be somewhere or expecting it to be somewhere. So many other forces can act on it. We need to focus on something that is of general use, and that is the inflation rate, which thereby clarifies decision-making both for businesses and for households. That's something they can count on, that we're going to keep inflation close to target.