Temperature extremes and firearms protection

I think most of us in the continental US are dealing with cold today. How extreme depends on where you are and what is average in your area for January, I expect. Anyway, as the title states, I'm looking for some information on protecting firearms in extreme temperatures.
I have a couple of rifles that I noticed the accuracy went down on. I blamed myself mostly, but once I acquired a bore cam, I realized that corrosion etching and the resulting copper fouling was the likely cause. I have always thought I took great care of my firearms, so I was not at all pleased with myself when I discovered this damage. It's not something you can see with the naked eye, and if I were not particularly picky in my accuracy/precision expectations, it's something many would ever notice. But when a hand-lapped custom barrel more than doubles it's average group size, it gets MY attention.
Anyway, it's -0-F here right now. Last night, the low was -20F. The air is awfully dry at about 30% humidity. But I conducted an experiment and if I leave a chunk of bar stock outside for an hour, it does indeed frost completely over when I bring it back inside. I have also observed exactly the opposite condition in August, when the temp is in the 100s, the humidity in the upper 80%, and I take the same block of steel from my temperature/humidity controlled loading room to the shooting bench, excepting it is covered with condensation as opposed to frost.
So the point of all this is, how do you owners of precision rifles/competition rifles prevent bore damage? Obviously, a good oil/grease treatment is the way to go for storage, but what about stuff you are shooting every couple of days?
Perhaps I'm obsessing over a rare occurrence. I just want to make sure it doesn't happen again, and swabbing thick oils in and out everyday becomes cumbersome, to say the least. I was using Ed's Red as a short term protectant before. But now I don't trust it.
Any constructive ideas welcome, and thanks for looking.

This has worked very well for me. https://www.eezox.com/

On hot, humid days when I am taking rifles from my cool but dry basement or air conditioned car into the outside to shoot, I try to leave the rifle set outside long enough to get warm. Before I shoot it, I run a dry patch through the barrel to make sure there is no build up of moisture or any oil left over from cleaning and storage.
It takes some time but seems to work fine.

When I’ve been out in the cold all day I let my rifles sit outside the safe and stabilize the temp to dry prior to wiping down and cleaning. I don’t have to worry about humidity here in the house in Vegas so plugging in my dehumidifier rod for the safe isn’t necessary. If I move the safe to the garage then I will make sure it’s plugged in.
I just keep my wood stocks covered with a good wood protectant and the metal covered with a light oil. I also have them in silicone impregnated gun socks if I’m not shooting them for awhile.


Sent from my iPhone using Tapatalk

I use a dehumidifier desiccant type and golden rod in the safe. I also wipe down with barricade prior to going back in.

As you noticed going from colder to warmer causes condensation. That's how the golden rod works. Heats the air in the safe to make it warmer than ambient temp preventing condensation corrosion.

I allow my firearms to sit in my reloading area for a little bit, few hours as I unpack and sort brass and other things before cleaning and wiping down. Haven't had an issue, knock on wood.