Ya, at least here in the Denver those covers cause more issues than help (wind constantly rubbing, UV, etc) but you may very will live in a good spot for one. I know a lot of people do, especially in the south.
If it were I, I would use some semi rigid packing foam that you can cut out and build up a house around the horns so the cover never comes in contact with the horns and is supported by a mound of packing material. Some of that stuff that is like styrofoam, only more flexible.