While true, I think if the population they derive their income from isn't merely of that of their riding, but the average of their region instead (entire city/province, not just the riding), then it will seriously minimize the impact.
But even without that, this would strengthen the vote of low income areas as there will be less competition, making those that represent high income areas worth less since they tend to be outnumbered by low income areas. You either get a high wage, or have an easier time not only getting voted in, but having more peers representing people in similar situations.
Still think spreading the average is better, but overall I think it can work better than it currently is either way.
It sucks that grocery stores make these labels based on where the company that sells these products come from. I mean, CocaCola and Red Bull both have a maple leaf tag at my usual grocery store because they have subsidiaries that are Canada based, though I last I heard the syrup as well as the bottles come from the US for Coke, and is only bottled in Canada.
At the very least, outside of the produce isle, it is pretty easy to buy mostly local. We produce so much base foodstuffs that a general guideline will mostly work. Anything that's grains, fruits, meats, and diary are probably Canadian, aside from tropical fruit at least. Nuts are hit or miss, but a lot of them come from California. Unfortunately a lot of rice is also from California. Oranges are almost all from Florida, so the first thing most people should do is cut oranges from their diets, preferably permanently and find a new favourite fruit like blueberries or apples.
The unfortunate truth though when it comes to groceries, is that it's nearly impossible to give at least a little bit to the US with your purchases. Less than a half dozen companies own more than 80% of the products stocked at most grocery stores in Canada, all of which I believe are American. The maple leaf tag just means that there is a Canadian company in between the owners and the product.