As someone who worked 33+ years outside in all weather as a mail carrier in Cleveland winters -- keeping the fingers DRY is primary. Even thin gloves with a wet-proof outer layer. When carrying mail, I wore thin leather full-finger 'driving gloves' with a pair of surgical gloves over that - OR I wore TWO pairs of surgical gloves without the driving gloves... Dry and toasty, even down to -10°F and I still had the dexterity to 'finger' through the mail... Yeah, I went through several pairs of surgical gloves per day - mostly due to wearing trough them, but it was worth it!!! Bike riding doesn't need the fine dexterity so a thicker waterproof glove would work for the outer layer.
Shoes/boots -- again, keep the feet DRY. I used brush-on silicone. I pre-treated my driving gloves, shoes and insulated leather boots with several applications of Pecard Silicone and I was good for the whole winter!!
Re-apply more before the next year. My insulated leather boots are going on their 14th year!!!
.