I've worn my Decathalon B'twin 700 bib tights in -3 and been OK. I was going a fair clip mid you!
https://www.decathlon.co.uk/aerofit-700-thermal-cycling-bib-tights-id_8343083.html
http://road.cc/content/review/111974-btwin-7-membrane-bib-tights
Same for me but not the bib style with some outer shorts on top if it's a little chilly. PlanetX overshoes for my feet.