There is only one way to know for sure: mount them and see if they rub. I think there is a good chance they will, because I know how little room I have with my 245/45/19 new Nokians.
There is a 1.7" larger diameter with the X winters, that is 0.85 inches larger in every direction. I know there is less space than that from the front tire to the condenser shrowd openings on my S, but my Nokians have 11/32 of meat on them; not sure about the Pirelli's.
I wouldn't do it even if I could, because of the reduced range and reduced snow traction due to the larger contact patch.