40F is about my tolerance for riding. Otherwise have to wear too much gear and body gets too hot while face, hands, and feet are freezing. High today, 32F.
If your core temp is skyrocketing whilst the extremities are cold,
it's not too much gear, it's the wrong gear.
I've been cold weather riding my whole life -- FFS I'm from Ski country -- and I see people make the same mistakes over and over again.
First mistake is thinking that a big heavy jacket, as thick as possible, is the ideal. Really you don't need as much on the body and something like a ski suit over normal clothes works better. Just be sure it's easy to unzip as you will find once you get up to temp, you need to vent your torso in the front. A good ski suit should also be wind-rpoof on the legs. Protect the upper thighs from wind burn.
Second is footwear. No you can't just wear normal shoes or normal boots. Get waterproof boots (which tend to also be wind-proof) a size too large, so you can wear ultra-thick wool thermal socks underneath. If your feet get gold decked out like that, something's wrong. Oh and if you can't get waterproof boots -- this'll sound weird -- normal rugged boots can make do, just put plastic bags over your socks. A proper set of "rubbers" / "mucklucks" with good socks works as well. Feet cold and it's above 0F, you're wearing the wrong socks and shoes.
On the head, get a motorcycle helmet, or half-helm with goggles. If you wear glasses the latter with a ski mask is better if the seal on the goggles is good, to avoid fogging up.
But the biggest mistake is the hands.
Gloves are NOT your friend, at least not alone. If you wear wind-proof
mittens that fit well with no gaps to your shirt/jacket and your hands get gold, get better mittens. Keeping your fingers together for warmth is superior to the best gloves in existence if it's about staying warm.
Which kind of sucks for e-biking as I found out last year, having to take them off to manage the control pad. but you can wear gloves if you get something simple for your bike. Handlebar muffs.
Because most of what makes things like normal gloves less functional is wind. So tie those around your bars and off you go.
The muffs on their own aren't enough, and gloves on their own aren't either, but combined and boom, you're fine. It's like keeping your gloves in your pockets.
And remember, the Ski shop is your friend.
Probably why despite my disturbing lack of faith in my LBS, I'm glad in the winter months they're also a ski shop.