Errr .......... I dont think you are right mate. Ive regularly dropped pressures in snow for increased grip, although narrow tyres are defintiely better raising them isnt going to make the tyre any narrower, it will just be harder.
I remember getting totally stuck in one of my old Deltas, dropped pressure as much as I dared and it was like a different car, the snow that had stopped me now wasnt an issue at all. Id add that the construction of an MPSS means it wont get much more of a footprint, but anything is better than nothing
Must confess that I thought the same but was temporarily deferring to the judgement of the resident tyre guru This would tie in with the logic of winter tyres being softer as per my earlier post.