Trailers and Ice don't mix even with chains. My rule when towing is .....when it starts to ice up.... just get off the road.
Couple days after Christmas 1972 I was towing a trailer down I-20 at about 25 mph with the flashers on, in a freezing rain, somewhere near Sweetwater Texas, the sun was going down and I was skating across every bridge trying to get to a town, they closed the interstate down and I was stuck for 11 days because of an impassable ice-storm.
Sweetwater was the most wonderful town in the world my wife and I could have ever got stuck in, God Bless Texas.
(special thanks to the Smith family for taking us in)