When we bought our RZR, we hauled our toyhauler down to the RZR dealer to make sure it would fit. That's probably your best bet.
That being said, Our garage is 9' and our stock RZR 900 fits in it with about a half inch to spare. We wouldn't fit if we had a spare tire mounted on the back. I think you'd be fine with the slightly larger 1000 in an 11' garage, unless that particular Fuzion has some sort of extra cabinets etc at the front that make it actually shorter than 11'. It appears there's only OH cabinets standard.
You might want to be more worried about the height, if the Fuzion has both couches and a queen bed in the back. But that's a pretty easy thing to figure out once you're looking at the trailer.