The size of the unit on a 23 hp tractor must take into account what you get for snowfall. Last winter we received over 220 inches of snow between Halloween day and the end of March. Snowfall continued almost uninterrupted from very late October until 1 February (we had a small break around Christmastime). We're at the foot of the Tug Hill Plateau, off the eastern short of Lake Ontario. Eleven miles from here, in Barnes Corners, they measured over three hundred inches last season.
So, the question isn't strictly, How much can the tractor handle? It's more like, What can I expected to handle if where I live gets hammered?
I have a 23 hp Kubota (17 hp at the pto). I'm happy enough with my 48" Loftness. With as much snow as this area can experience, more is less.
I'd opt for one of the two smaller units. And I would choose which one on the basis of the quality of a dealer's service. To save a hundred dollars and get poor service is no savings at all.
Doug
BX2350 w/rear hydraulics, fel w/Markham tooth bar, Loftness 48" 3ph snow thrower, and other stuff.