Yeah the key is windproof. If you layer properly with windproof jacket, you can be super comfy with what’s in your closet. But, here’s what works well for me down to -5f (past that I start taking shorter rides)

• Windproof rain jacket (shell is ideal), and if it’s really cold (<10f) windproof or snow pants. Windproof upper layer is key
• Wool long johns and long wool socks. Normal non-cotton winter pants over that
• No cotton… you may get away with it on an ebike though as layering above wool long johns
• Bar mitts are awesome, anywhere below 50f, you can get cheap ones on amazon
• If you’re comfortable with it, it’s a lot easier to keep your head warm without a helmet imho. Just pull up a normal hoodie and then waterproof shell hoodie over that with a wool beanie and neck warmer you’ll be good down to 20f. Past that, a cheap face mask does wonders actually! Even down into the negatives (I figured that out during covid)
• Any frozen precipitation requires ski goggles. Clear is best imo and they can be pretty cheap.
• Windproof boots for below freezing and DO NOT tighten them up. You want to keep the blood flowing

Thick khakis with thin sweatpants underneath are a pretty good alternative to lined pants.

Like the other guy was saying, wool socks and a ski jacket also make a big difference.

It’s also possible to get completely comfy in 20° F with high wind, by either going the snowboarder route (earmuffs, goggles, etc) or by spending a bit more and get a full face longboarding or skydiving helmet (much lighter/smaller than a motorcycle helmet).