Winter Running

Hi! I am very new to the running community and training for my first marathon in April :) This week I have been running into some trouble training with all of the ice in NYC. I really dislike running on a treadmill but can do it for the shorter distances need be. I typically run outside and just layer up. My question is: What do people do for long runs when it is so slippery outside? Hoping the ice melts soon but let me know if you have any suggestions. Thanks!