Richard, are you saying that the house section of the tractor is totally open to the run section? So that there is no wall between the house section and run section? That's a pretty common tractor design.
If so, and you are having problems closing that area between the housing section and the run section, can you just cover the run? Even if you cover it with plastic or a tarp, it might help. Straw bales against the side would help insulate, also. You could even put plywood or some other type of panel on the sides of the run, over the wire, for the winter. Then the entire tractor becomes a coop, basically. It would even help to cover part of that gap, using something solid. Leave just enough opening for a small pop hole, but have the rest of the gap be enclosed by a piece of plywood. That would still keep a lot more heat in than leaving it totally open.
It's a little hard to know exactly what would work best for your tractor, without knowing a little more about what it's like structurally, but I hope you get some ideas that help you. You can always post a new topic here in the coops section, on winterizing a tractor, to get other opinions. Plastic or tarp might be a good way to go, if you are just trying to get through the next two weeks, before moving them to a new coop, depending on the weather coming.
It's hard to say what happened with your RIR hen. It could have started with pecking or it could have started with frostbite and then turned into pecking. Can you dress warmly and spend a little time watching them, to see what's going on?
Chickens can start pecking on each other for a lot of different reasons. Do they normally free range in the warmer weather? Are they spending their time huddled in the housing end, trying to stay warmer, or using the run section, too? It's always tough if they have to adjust to any kind of stress, like more cramped quarters than they are used to, cold or anything else. I think some breeds or individuals are just a little meaner than others, too. How many chickens do you have in your tractor?
You could try spraying her comb with BluKote, so it's not as attractive to peck and try to give them something else to do. You can try tossing scratch or other tidbits out to them to search for. If it was me, I would pull her out and treat her, even if she had to live in a cat carrier temporarily. If she's already a target, reintroducing her would be a challenge, though, in cramped quarters in the winter. It's pretty ugly to see a chicken pecked to death, so I'd try to do something. I would definitely keep a close eye on her. Maybe you could post this as a separate topic in one of the other sections and get other ideas. There are even rings you can put on the aggressor(s) to keep them from closing their beak all the way. I've never used them, but one of the members on the forum has.
Good luck with all of this. Once you get through the first year, you should be all set. Every season has it's own challenges.
