Exactly why I ran 245/40R18 on my B6, and was meticulous about checking tire pressure. I lived in the city for several years and my snub actually was still in one piece when I changed it.
Ya, in SLC they use MgCl2, magnesium chloride, which is much more effective than NaCl but much more corrosive as well. I try to avoid the highway during the winter or if i have to rinse my car (underneath too) within 24hours