BMW 320d Tourer here.
If I can’t
leave it at home and take the bike!
(which is first choice), then it’s all about commitment. Weight in the back good, snow tyres (which I don’t have) supposedly better. Keep sensible momentum going, and don’t back off.
I really wouldn’t want to drive it in heavy stop start traffic – that would be horrendous (silly 255 section tyres don’t help), but country roads seem to be pretty OK. Don’t go too fast, but keep sufficient momentum, turn in a bit early, keep the power on and countersteer as appropriate.
To be honest, whislt the beemer loses traction far earlier than my old Passat, it’s far more controllable once it is sliding, so actually is more capable – the VW would just carry on in a straight line once it had broken loose. The BMW you can wrestle into some form of shape. Last christmas I was the only car to make it up the hill to the house we were staying at in Norfolk, and that was mostly down to confidence and momentum.
As above though – if it’s like that, then better leaving it and home and riding the bike. Really want to go and find an empty carpark though!