If they're anything like my 325 it's pretty much all scaremongering. I never came close to crashing in two years of winters on summer tyres - you're far more likely to have trouble moving than crashing.
Having said that, the only time I got stuck was when I was trying to bump up a kerb in about 2 inches of snow and trying to get off the icy drive which is a really steep angle. Once you're moving there's not really any problem.
Keep the revs low (pull off in 2nd and change quickly to 3rd) and if you start struggling rock the car back and forth until you get out of the rut you'll have dug yourself. I kept a shovel, snow socks and some bits of old carpet in the boot just in case but I never used them. Another trick I used is to put something heavy in the boot, I used all of the spare weights for my Dad's dumbells and a load of snorkelling gear mainly because they were heavy and already in bags so easy to throw in. I'm not sure how much difference this made but I haven't got stuck after adding it.
These cars will never be as good as a front engined, front drive car with 3 inch wide tyres but they're not as bad as people make out.