Is there a certain point where it is so cold it is unsafe to ride a motorcycle?

That is exactly what happens. The tires are cold, and the road surface is cold and holds moisture. Bikes have extremely good traction when its warm and you match or exceed the road temp. But in the cold, traction goes out the window. Sportbike tires are not made for winter driving. they dont have a flat contact surface either. Other than not really liking riding in the cold, that is the main reason I do not ride when its this cold.