Auto Express magazine had an interesting article a few years back... Summer vs Winter Tyres , AWD vs FWD... completed in 2 Ford Kuga’s at Milton Keynes Snow dome.
I cant remember the exact distances but in summary the results were something like...
Summer Tyres -
FWD car with Summer Tyres went about 3m and then slid back down. So basically went no where, and actually ended up worse than if car had not been driven, as slid back past start line.
AWD car with Summer Tyres went a little further up the slope but not by much. However it too, slid back down , but stopped only just ahead on the FWD car.
Winter Tyres -
FWD with Winter tyres drove about 3/4 of the way up the slope. Got stuck but did not slip back down.... an amazing achievement when you think how steep that was.
AWD with Winter tyres drove all the way up and over the top and repeated it several times... just for fun!
Skinny tyres and Winter Rubber will always win over Summer Tyres irrelevant of how many wheels are driven or how wide the rubber is.
@Wxm also makes a very good point re traction and braking.
I had a very scary moment a few years ago in a 4WD car with wide summer rubber going down a sharp hill in a light sprinkerling of snow / ice and I was only doing about 10mph!
Last few years we have had Continental Winter Rubber on a cheap FWD runner about. Used to love the looks I used to get from stranded 4X4 owners as I used to drive around and up / down hills with ease. Sadly we sold that. So back with the rest of the majority of peeps on Summer rubber for the time being.
Therefore staying in doors as much as possible with the recent snow !
Jungle