I remember one afternoon when a bad storm was rolling in here in Colorado, and the temp was dropping. It was one degree Fahrenheit at quitting time, and I decided to hang around because one degree, meh, I might as well wait for zero. So I waited half an hour, and it was zero, and I rode 6 miles home.
In low temps I have trouble keeping my visor clear. Anything below 20 F anything you can put on the inside surface will not keep ice from forming, especially 2 oval 1" flares where your nostrils sit. So, if you go any distance, count on having your face exposed. I chew gum when it's really cold, to keep my facial muscles moving to help keep my face warm. I think it works, have not read a dissertation about it though. I suppose I could get a full helmet, instead of my 3/4, but I love my 3/4.
I ride all year, and so I routinely ride in 5-15 F on winter mornings. This morning we woke up to some snow (we haven't had a lot yet this year) and I got my ride in to work on a very slick arrangement of road surfaces. Oh well, nothing I haven't seen before.
On slick surfaces, if I may give some advice, you can use the gyroscopic effect of the wheels to have good control of your bike. The bike will never fall over on its own, as long as the wheels are moving. So, as long as you are traveling in a straight line, keep that in mind. The bike just wants to stay upright, and it moves right along as you gently apply engine power, and it slows down when you gently apply the brakes. So, in traffic, as long as you are far enough behind the vehicle in front of you, and if hopefully there's not some fool behind you tailgating, you have nothing much to worry about. Obviously, there is always a chance that something unforeseen throws you off your path and knocks you down, but you are NOT constantly about to bite the dirt, it is much more stable than you think. If your back wheel starts to break out to the side, you may have too much throttle, so back off a little. All that is happening is that your back wheel is trying to overtake the front. Once you close the throttle (only as much as necessary) things will straighten out again.
Another thing, when you are on a multi-lane road, and your scooter has enough power, I strongly recommend not riding in the right lane. The right lane is dangerous for several reasons: 1. Obviously, a vehicle may come skidding into your path from a side street; 2. Vehicles coming from side streets are carrying large amounts of snow and slush with them from the neighborhood streets, and it is deposited in gnarly curved ruts that can really mess with you; and 3. the closer to the crown of the road, the more level the road surface. Between trying to resist slipping off the side of the road into the gutter, and storm drain covers, the right lane is bad news in the snow.
Hope this helps. Oh, and take turns very gently, hold the bike up much straighter than normally, and steer like you're on a 5-year old's bike with training wheels.