I find the winter baselayer very warm, so wouldn't be wearing it until temperatures were down to 2 or 3°C. You might feel the cold more than me though, I'm still wearing summer baselayers!
agree, i feel the cold definetly more.
Last weekend, 9° i had the pro baselaye ss, and odlo winter baselayer ls + Longsleeve Jersey and after 2h i put on the wind jacket.
I find the winter baselayer very warm, so wouldn't be wearing it until temperatures were down to 2 or 3°C. You might feel the cold more than me though, I'm still wearing summer baselayers!