I've been lurking, but it is time to say something. Jean is right, that hair is there for a reason, and Mother Nature knows best. I've been doing demos for years including 4-H since 1986. If you must trim something as you seem to want to do, then clip the goat hairs, and blend in with a #7F blade into the neck, also clip the bridle path and nothing else. 26 degrees is below freezing. Pleas do not clip the ears as they will frost bite.
Now for a horror story concerning the head and neck slinkies that are so popular. Never leave your horse unattended with one on.
We have been showing for many years and after a bath at the end of the day we put the slinkies on, fed and retired. Never had a problem in like 10 years. But, problems can arise, as minis seem to find a way to hurt themselves. Once at a show I awoke early to go feed before the classes started and my grandsons gelding had obviously rubbed his neck or face, whatever with his linky on and now the slinky was rubbing his eyes. I took the thing off and both eyes were blood red. Thank goodness I had some ey ointment with me, but his lids were swollen, and his eyes were still squinted when he had to enter the ring. Now I only use them after a bath, with the horse tied in the isle while being watched and take them off when not attended.