Obviously you need to look at two parts of Canada, because the U.S. border area--let me call it that--has a population density that is quite high. Certainly in parts of Ontario, and in parts of Quebec, the density will be higher than it is over here in France. I'm talking about the belt along the lakes and along the St. Lawrence. There shouldn't be any problems in terms of telecommunication service there.
If you move further north in Canada, obviously the revenue potential for companies is much lower. It's easier, for example, to provide mobile in certain areas. But my experience with Canada is that even in areas that I wouldn't call sparsely populated, there have been difficulties in the past in getting mobile signals. I take it that there is insufficient competition between operators to try to provide better service for customers.
But you are correct: in areas that are sparsely populated, the cost of providing networks will be difficult. It is important for governments to designate these areas and to try to ensure that networks are built there. As I said in my earlier question, the greater the number of operators you have, the more chances you have of ensuring that you find someone to build the networks there at the lowest cost.