I had a Mercedes 4Matic AWD. It was the best vehicle for snowy roads and ice. As you stated, as long as you keep it on road. Mercedes have driver/traction aids that reacted faster than I could. Your Porsche is probably similar.
And winter tires are essential. I have a performance AWD vehicle but here in Phoenix I run UHP summer tires (Pilot Sport 4S) and would not be comfortable driving those tires in icy / snowy conditions even with the car’s sophiosticated AWD system.