I used to never be able to ride in sub-freezing temps with a balaclava fully covering my nose and mouth, and glasses, without major fogging problems. My commute is pretty hilly and I'm not fast, so I was always huffing and puffing and breathing super hard, such that wearing glasses with balaclava was impossible. Even my ski goggles I purchased a couple years ago would fog up.

But today I tried my glasses with balaclava on my e-bike, so I wasn't breathing as hard AND doing 16-20 MPH, and it worked great! No fogging at all unless I stopped. It was about 26°F when I left the house this morning.