Going to be hard to justify a third new bike! You see, when I leave Japan I am going to try to sell the fixed-gear commuter, and leave the road bike for riding on family visits*, meaning I need to replace both of those in Canada (not sure of the road bike, I so distrust Ontario drivers and even more in the 'burbs and rural). So the third (or second) bike is the off-road bike. I'm a tall guy, and I am used to big wheels, so a 29er is it. Also I would not go full-suspension, eschew hydraulics, prefer steel, and even prefer full rigid. Some of that is luddite, but some of it makes sense for a winter/summer do it all machine: a fat bike. What's that?! You put enormous tires on a 26er, making the diameter the same as a 29er, having about half the suspension of an FS bike, but far fewer moving parts, and a tonne of float. Goes over all but light snow, which we don't get near Toronto, and rolls over any damned trail.
In the past two years the number of fat-bike frames and complete bikes have exploded, and I will not list them all, but the cheapest/easiest options are the three series of complete bikes made by QPB:
Surly Pugsley Series
Salsa Mukluk Series
Surly Moonlander (overkill!!)
*Because the humidity's too evil to try to run for training around Tokyo in the summer.