If we go there will be a benefit in that a couple more years residing in Canada and I would qualify for Old Age Pension (Canada has two systems, one based on earnings and the other based on residency).
Don't forget universal health care. Which is an extremely important thing to consider in old age, since that is the most likely time that one might need extended care of some sort.
I still maintain dual citizenship in both Canada and the United States. Depending on when I retire, I have actually considered relocating to Canada for a few years to be closer to family. But I admit, it isn't going to be an easy transition considering I have become pretty accustomed to Florida weather. I guess there is always the possibility of maintaining two residences, one for winter and one for summer.