My update: On Sat. I ran with a colleague from work, 20km in the morning and 5km in the evening. On Sun. I did 12km in the morning and 10km in 52min in the evening. As the weather gets colder, I bike less: only to go to work. In the evenings I try to run a bit more, at a bit faster pace.
Here temperature max 11 and min 5... and chilly wind. After training on Sat. I went to the spa and stayed there 3hrs to accumulate heat!!!