We had close to two weeks here in Wisconsin where the temp never got below freezing and mixed in there we had rain. On the first day below freezing I drove my truck on the lake I fished with no problems. Just have to watch where the in-flowing streams are and be aware of any springs. In mid winter a three day stretch of 40 degree weather isn’t going to kill the ice. Use common sense and don’t be a brain dead cowboy and you’ll be fine.