RE: I rediscovered Borebutter this weekend.
I've never opened the Hoppes to reveal what's inside, but I heard it is a product very similar to T/C 13. That one doesn't freeze in overnight 20ish degree temps. I recall that from my earlieryears muzzleloading. Anything colder than that won't see me outdoors with a gun anymore - unless it's a shotgun hunting rabbits for a couple of hours or-so max.
I might think differently about staying out there -- if I had some private land access.