It's so beautiful there and I can imagine it's even nicer when it's covered with snow and the lake is frozen :) But I would never drive there with my car at that time.. It's far away from the highway and I wouldn't like to drive on these serpentine combinations with snow on the road :)
I agree with you! 20º is definitely too cold! But let me tell you that people here swim in the Rhine when it's only about 16-17º :D brrrrrrrrrrr