Not very well. When it gets cold enough, the water in the ground freezes and expands and basically "squeezes" the fiber. The "1"'s, which are long and skinny,

Not very well. When it gets cold enough, the water in the ground freezes and expands and basically "squeezes" the fiber. The "1"'s, which are long and skinny, can still slide right through the fiber but the fatter and wider "0"'s sometimes get stuck. This causes the fiber (Internet pipe) to get clogged and, eventually, stopped up completely, similar to how car crashes on the Interstate can quickly bring vehicular traffic to a standstill. (Source: I was the Senior Network Engineer for a FTTH ISP, until just recently.)