bianchi pista workhorse, cannondale r1000, mountain bike fixed conversion
i haven't had any problems yet with 700x23. well, one, but that was my own stupid fault. i think it has more to do with how you handle yourself. anticipate icy patches. and if you see one coming, either don't turn till you're past it, or skid purposely--that you have some control over, as opposed to skidding accidentally, completely surprised.
with all the talk of winter riding, i've been prompted to examine my own winter riding style.
Soma Rush, Fuji Cross, Raleigh Technium Mtn Bike, Ross 10 speed with Shimano 600.
best tires I've used for snow and packed snow are Geax Blades. Very sharp widely spaced oval knobs. they grip like mad in deep snow and packed snow alike, and don't load up with snow.
I cruised down a hill on packed and rutted snow this morning around 20mph (coasting) Both ends got a little light a few times, but I never lost it, and never needed to touch the brakes. I'm guessing 20, I usually cruise down that hill around 28, but the snow and knobs slowed me down some.
See, in WI it was a way of life. Every year there were times when you couldn't so much as walk to the corner store without traversin' a 30' patch of sheer ice. It gets such that you know how to walk on it as a human being*-- and biking sorta follows.