The way I understand this situation is,
a 'cold' air/fuel mixture is richer because of more denser air,
a 'cold' combustion chamber is hard to ignite,
a slightly lean air/fuel in a cold chamber is even harder,
whereas a slightly rich mix will wet/flood the chamber,
if the rev range is increased the mix is easier to predict/control,
this is the basic problem with any air/fuel mix.
I also suffered cronic problems lately in the cold, the coil packs were cracked which usually shows up in the high rev range when each pack is firing around 16 times a sec, but on a cold DEWY morning everything is damp and the cracks act as conductors until the heat disperses it.