Worth Mentioning.
I have a 3720 Cab with a 59" Front blower. I'm running unverferth 6" (each side) wheel extensions on each side with loaded R3's. I'm running 66" (I'd be a little over 71 in the wide position) in width in the NARROW position. I was worried last winter but ran this way the entire winter. Other than maybe a small compressed tiny bit of snow, the extra width didn't bother me a bit, even in maybe 15+ inches of snow.
Corners weren't an issue at all. I was worried I'd have to take them off but I didn't need to.
I do agree that the 3x20 series could take a wider blower. In all honesty for most snowstorms my 2305 could easily handle wider than 47" also.
It is expensive (close to 5K between the blower and the front mount, kit, etc.) but it works nice.
However I would like a rear one to be able to leave the loader on the front to break down banks, etc. If I ever upgrade to a 4720 I'll either get a rear blower or a high capacity PTO pump and a skid steer mount hydraulic blower.