You have a problem with your 1er fishtailing? Isn't that the best part about winter?
Honestly, just be gentle. You don't have to treat it like a baby. But with DSC on (default) your tail shouldn't be spinning out, even if you give it moderate power. The system handles my car just fine when I don't feel like having fun, and when I do, DSC/DTC come off.
What kind of winter setup (wheels/tires) are you running?