Is it in any kind of enclosure?
Discussion
Yes it’s in an enclosed metal box. Since it’s enclosed and the depth and width of the box are basically the same, there’s really no way to
Insulate that part.
That's not true. You can wrap the outside or get a larger enclosure and insulate that. You could also get a heat tape to wrap around the inside of the box, which should give enough heat to keep it from freezing, but that would work better with insulation.
This is what I’m working with. 
Oh. You could cram an old school lightbulb in the space below and that would probably work if you can't get a heat tape, though, I think you could fit a heat tape even in those tight quarters.
That’s actually a good idea. There is a 110 power plug the bottom of the box. I’ll have to look into that once I get it thawed out. Thanks for the idea.
You're welcome! I'm dealing with my own freezing issues, and I've learned a bunch. Happy to pass ideas along that keep the water flowing!