Layering under a wind resistant shell is the way to go I find.
I usually use a very thin shell jacket and pants and layer accordingly underneath. The kinds you can pack into a pocket if you don't need them.
Windstopper or even softshell is usually way too hot for me. If you need ventilation holes the fabric isn't breathable enough. Hence, wind resistance but not complete wind stopping.

Back in the military we would hang out in simple BDU's at -4F and just put enough layers underneath. At the coldest it would get we would be pretty stiff due to all the clothes packed underneath but at least we weren't sweaty. Sweat and cold is a deadly combination