The justice department attempted to get Statistics Canada to do exactly that. The general social survey does not do any polling in any of the territories for precisely the reasons we're talking about. People are too isolated, too vulnerable, and they simply have too low of a response rate on anything that is voluntary.
So special pilot projects were carried out by Statistics Canada not once but several times, attempting to find a way, some way, to get people in the territories to respond in large enough numbers so that the GSS data could be valid. It could not be done.
The Department of Justice, because they were intent on showing an increase in crime rates in those areas, decided they would go ahead and publish the data on their own with big warnings saying it was not valid data but it was the only data available.
You can go on the Justice Canada web page and read about all of the efforts they went to in trying to do exactly the kind of thing you're describing.
Statistically it does not work, and unless we want to go back to sort of pre-governance days, we unfortunately need a mandatory census in Canada.