Steve, I've run my 240 and 740 Volvo's in Rochester NY for many years with 4 unstudded, Gislaved Frost snows and had no problems.

I tried a set of Nokian Hakkapellita 1 with studs on the 740, kinda wish I'd skipped the studs for the reasons Steve Ringlee mentions.

This year, I'm trying the Michelin Alpin on the S**b. I think they'll be fine in the snow and are supposed to offer excellent wet traction. I'm using steel wheels on the S**b, so I'll throw a set of those European cable chains for when things get really nasty.

There's an excellent discussion of the different needs for snow tires in different climates on the Nokian web site. They talk about snows for central Europe (mostly wet, some snow), being different than the Nordic tires (almost all snow). Worth a read & I'll post a link.