Snow isn't the same thing as cold though. I can believe Boston getting slightly more snow than Toronto, it also gets more snow than Chicago (where I used to live). But Chicago is way worse than Boston for cold, it stays below freezing much more consistently as opposed to the freeze-thaw cycles in Boston that tend to melt snow after a week or two (so a given snowstorm in December sticks around for a couple months in Chicago), and it gets extreme cold below 10 or 0 degrees F much more commonly than Boston does.

Looking at wikipedia, Toronto looks very similar to Chicago in terms of winter climate, so I would say it's a noticeably worse and longer winter than Boston based on my experience in Chicago. Technically Toronto gets slightly less snow, but the difference is marginal, 48 inches per year on average versus 49 inches on average in Boston.