This combination served me well for 7 winters of bike commuting 12 miles each way whenever the temperature went to 10° or below, also worn when snow was on the ground while biking at very cold temperatures. Proven effective down to -8°F.



Note: No steel toe, heat robbing box, in these boots.

It really comes down to if your feet run cold. I've worn neoprene shoe covers on road shoes at about 8 degrees F and been fine. On the other hand, I know people who get really cold feet while fat biking in Sorels, something that I would be sweating in even at 20 below zero.

Consider NEOS available with stabilicer studded soles .. over your boots on plarform pedals?

I was drooling over these this past summer cuz I just started using cleated pedals/shoes & was fantasying about this coming winter. don't think they are in the cards for me at this time, I'm sticking with non-cleated solutions for now

I usualy make my own with the biggest 80 perc wool socks . i layer an emergeny blanket and a thermal layer inbetween the socks . cut a hole in the bottom and sew the edges of the hole tight around the cleat area
i works really well but my feet get cold but not as cold . i can make them as cheap at 15 usd or 50 usd .
Ive seen some one use wool boot inserts i might try those next year .
I use lake boots for commute they work well but cost a bit
i was thinking of getting some fizik winter shoes for road but inthink my hack works well enought that i can do some outdoor riding during the day and a snlpin session at night indoors .

Maybe look at Gripgrab.

https://www.gripgrab.com/collections/shoe-covers

The Race Aqua might work for Socal. The size chart says 3XL fits US 14.5 to 16.

I have the Race Thermo high vis for road and Race Thermo X for MTB and gravel. They are very well made and perfect for North Georgia winters where low temps are typically around freezing. I can post photos if you want. Just let me know.

Gripgrab does not ship to the US. Wiggle is the only place I've found them.

wiggle.com | GripGrab

I'm going to buy the Race Aqua high vis from Wiggle as soon as my size are back in stock.


-Tim-

I swear by the Pearl Izumi WxB P.R.O. Barrier shoe covers. I commute 10 km each way all year round on the west coast of Vancouver Island, in Canada. It rains on average about 2 meters a year here, and most of that is Nov to Feb. As I write this it's 6 am and it's rained 25 mm since midnight. I'm on my third set of these since 2012, and they've never let me down, but they do wear out eventually. The bright yellow ones are highly visible, but they only lasted 1 1/2 seasons. I wear them over light weight leather road shoes (spd) and even down to -11C they're fine for a 25 minute ride.

I looked at GripGrab. The only MTB covers are the RaceAqua X, RaceThermo X, and Arctic X, at $57, $65, and $82 respectively. Limited reviews do state the RaceAqua has something of a slimmer fit-- same problem I have with my Pearl Izumi covers.

I already received my AeroTech covers, which are definitely big enough to fit over my CX shoes, and an absolute bargain at $29. A pricepoint I'm good with, as this is a product I bought hoping I need to wear them... like never. I mean, this is Socal. wear my bib tights less than 10 times a year. But I also hate sitting indoors just because it's a little sprinkly.

Sometimes I feel like having size 10 feet instead of 14 would solve a whole lot of problems for me. I'd probably fall down more often, though.

I have used them for clothes since I need tall sizes but for shoes they don't seem to go beyond US14/EU48 either. I have US15.5/EU51.

A reviewer says they fit his size 15 feet, & many say they run large.

For $30 it might be worth a shot.