I've found these to work really well, especially if you're wearing off-road shoes that don't suit using overshoes

https://www.seirus.com/...s/products/stormsock

https://www.lakecycling.com/products/mxz-304

Lake MXZ304 shoes/boots are the correct answer.

Call me madcap but Sorrel skidoo boots with flat pedals are spectacular on the fat bike. I'd run a little less beefy winter boot on a gravel bike but still stick with the flat pedals and the winter boots you already own. I tried leathe red wing work boots and found them a little too cold.

Probably in order of warmth:


insulated booties. The cheapest option and works decently.

"winter" cycling shoes. Much nicer if you need to walk around in the snow as the toe cover wont come off.

heated socks: likely thicker than your typical cycling socks, so you might need to have a different pair of shoes anyways.

"actual winter" cycling boots from Blivet, 45nrth, Garneau, etc... Might be overkill.

You can probably get the same level of warmth with regular shoes + booties + heated socks, "winter" cycling shoes + heated socks, with the advantage that in warmer temperatures you can use regular socks so you wont overheat like you would in those "actual winter" boots.

Below this, that's when you need to switch to flat pedals and big winter boots. Walk every once in a while to keep the feet warm.