Hi,
Biking in the winter can be tough. I find it a bit easier to keep warm on the MTB in the woods than on roadbike out in the open.
A suggestion:
- Feet: Neopren cover for your shoes (cold feet is not nice). You can even change to isolated soles.
- Legs: If you have short bibs (I recommend bibs/cycling pants with "straps" over your shoulders as they will protect your lower back and belly). Then you can simple wear winter running tights over them. E.g. winter-tights from Salomon. A shell-pant (water-proof) can save anything but rarely needed if you keep pedaling.
- Upper body: As suggested, use multiple layers. Thin sweat layer as first layer. Then midlayer and windbreaker or shell layer (e.g. water proof). If you keep the wind out, you can keep warm when your body is performning (dont stop pedaling

). Most times you can do with just the thin sweat layer and wind-proof.
- Fingers: Use gloves e.g. 3-finger gloves or normal fleece gloves with a wind/rain-proof shell glove over.
- Head: Use thin fleece hat if it will fit under your helmet or just an ear-band protection. Should be wind-proof on ears and able to cover the whole ear.
- Eyes: Light yellow or clear sport "sunglasses" (cover the eyes, wide).