Try looking into these:-
 

I am doing Everest basecamp this year so looking into warm clothing

Layers is key:-

1. SmartWool leggins/top/balaclava
2. additional Fleece layers
3. Alpacca Wool Socks and sealskinz
4. British Army Arctic Tent so when really cold you can zip up, fire/cook inside and even go to toilet if needed.

GLoves = thin material mechanics gloves / cheap motorcycle material gloves and main heated gloves or fur mitts plus mitts on handlebars

Layers is key and talk to youtubers who have done harsh climate travel on bicycles/motorcycles as they have video and knowledge to gain better understanding

Hope this helps with some ideas!

Good luck

Base Layers: I've become increasingly fond of Icebreaker merino wool base layers. In particular I like how they fight odor, even as the second or third week in the backcountry approaches. The 260 weight base layers are flat out toasty. Those are my go-to layers for the coldest of ice climbing days. Don't go lower than 200 weight for their base layers as durability becomes an issue. I'd also be very critical of the Mountain Hardwear pieces you select. Granted Ueli Steck has no problem soloing the Eiger in less than a day in those products, but I've seen a deterioration in their overall quality at times.