Winter tires (tyres) are superb.
A 4WD in the snow on regular summer tyres won't compare to a FWD car with winter tyres.
Yes it will set off fine and be better than most on bends... but 4WD does nothing to help you stop.. and ultimately where do you need traction for safety? stopping!
Virtually every car we see off the highway, on its roof or in a ditch is a 4WD. They come up from Vancouver, Seattle etc and think that as they have 4WD, they dont need winter tires - oops
I've driven a friends Ford Escape 4WD with 'all-season tires' on the snowy/icy highway here and it was dicey to say the least. Comparing that to my nasty FWD min-van with cheap snow tires.. The mini van is way more stable on the road and ultimately far safer - which obviously is rather important.
for my mind, if the GF takes the car to Whistler on a snowy or freezing day, I'm far happier to know that she's less likely to get into any difficult situations in terms of the 80 miles round trip per day commute in the snow or ice. Worth $400 of my money I reckon...