For the record... four wheels will spin on ice just as easy as two wheels....
IMO 4WD should be used cautiously, I have seen SO many more people in 4X4 spin out and wreck and all kinds of other stuff than those in 2wd trucks. I guess mainly because 4wd owners tend to think they are unstoppable or something... when i say the Blazer was RWD... it was actualy a selectable 4WD too of course, i just never used it. I have made it through every winter since i was 16 (so 7~ years now) with a RWD vehicle and never once went in the ditch, spun out etc...