Nice picture! My RS3 is tucked up in the warm today but I've always thought quattro is great in the snow. My first experience was in my 3.2 TT Roadster, we were at some hotel out in the sticks near Brecon, the snow came down quickly and many cars struggled to get out of the car park and driveway. In the TT you wouldn't even have known there was snow on the road. While all the traffic was static on the A470 I was able to cut across the deserted A4059 mountain road, the only other vehicle I encountered an old Defender. The TT was just as you describe faultless and fun and that was on the standard Conti's, as this was long before Winter Tyres were popular in the UK. I was surprised just how much grip and traction the TT had because the Scooby I'd owned before that was shall we say a lot more playful.
I can quite imagine the RS3 on winter tyres is brilliant in these conditions!