I run warm (I have a thermal layer beneath the skin 
) but I've never needed more than base layer, long-sleeved t shirt and either windproof or waterproof over the top, as appropriate. One layer on the legs, either Craghopper Kiwi or, if it's going to be cold and wet, I've some lovely waterproof Karrimor cycling trousers which were, apparently, police issue and are superb for cycling. Looped sports socks and a Buff or two for the head and neck. That lot will take me down to about -3 and even some of those will need to be unzipped.
) but I've never needed more than base layer, long-sleeved t shirt and either windproof or waterproof over the top, as appropriate. One layer on the legs, either Craghopper Kiwi or, if it's going to be cold and wet, I've some lovely waterproof Karrimor cycling trousers which were, apparently, police issue and are superb for cycling. Looped sports socks and a Buff or two for the head and neck. That lot will take me down to about -3 and even some of those will need to be unzipped.