No personal experience with SW48's except been with them on a trail ride. Even though they are heavy, to push a blade as wide as your thinking would be a stretch unless the snow was not all that deep. It stands to reason as blade width increases, the capability of the unit would suffer correspondingly.. In other words the blade would control the cat, not the cat controlling the blade.. If what your thinking would work well, I have a feeling those guys up North at Bombardier would have sold some thing like that as an option. Track length is good for side loads, and the track length is short for it to handle an 8' blade with authority.. Just my opinion, your mileage may differ...
Regards, Kirk