Hi guys, here's my .02
I live 5/6 months a year in the alps during winter (dec-apr), drive my motorbike there as well with winter tires, and have driven many different vehicles (have been doing this for about 10 years now).
Always have had winter tires, the ones with the little mountain symbol and the snow flake. On the road they have better grip etc. once the temps go under 7c then all weather tires or any thing else.
Don't get me wrong never have drive off road in snow, so no experience there, but on road I've never aired down. Currently drive a RWD and that needs chains on the rear once it really starts snowing, it has no weight in the back at all.
Someone just said about tire width, it's true what actual surface you drive on! Fresh snow on tarmac you want that small width tire (pizza cutter) to cut through to the tarmac, guess it would be the same off road to get to whatever is beneath.
Hard packed snow though, you are better off still with the official winter tires for grip, it's the compound that makes the difference!
For chains there is the always interesting discussion for 4x4, I know for FWD they go on the front, for RWD they go on the back. For 4x4 there is always a different answer. I've had people with 4x4's tell me when it's 40/60 put them on the back, 50/50 need them on all 4 wheels. You'll have to inquire with your official dealer!
Regarding chains, make sure they fit your tire size first of all! Then make sure they are at the correct rating! Our current work van is RWD 8 person Mercedes and therefore needs heavy duty chains (which I would get for any 4x4 anyway)
For the defender we only have 2 chains but only to comply with French law to have them with us in the car!
Hope this helps, but like someone else said as well, I'm not an expert this is just what I know and learned!
