Originally Posted by Bradbury
If you're an experienced rally driver, then sure, activate DCT or even turn off DSC completely. Otherwise keep DCT off except for situation where you need to allow for more wheel spin. Driving on a snowy road at 40-50 mph is not one of these situations. If you however need to crawl up some slippery back road, then DCT can be of huge help, if not even a necessity.
That's how I drive (winter tyres), most of the time I've found you don't need to activate DTC, as spinning isn't the best way to move on snow anyway. Better to be very gentle on the controls and bite into the surface, before you make it more slippy with spinning wheels. I activate DTC when I need it and then switch back to full DSC. But most of the time just normal driving mode.