I tried to take a corner at ~10mph and went straight into a snowbank. Luckily a helpful municipal plow driver (they exist!) pulled me out as long as I'd accept liability for any damages done to my car. He had chains on to make it down my road.
After getting off the dirt roads the roads were simply wet for the rest of my commute. This did not stop people from driving 5-10 under the speed limit. If you're going 40 and you hit black ice you're going off the road. Going 45 or the actual 50 mph speed limit won't really make a difference.