I would just make sure they have plenty a warm water to drink after feedings. I have given them oats before..but raw oats...never a processed oat??? So Im not really sure about that??? Im sure someone would chime in????
But for me as a rule..I dont give my goaties processed foods for humans...breads etc...I just dont think its good for them. But thats just me???
As long as they have a shelter out of the wind and plenty of hay to munch on, they should be fine. I doubt a warm oat mash will hurt them, but it'll be more for your benefit than theirs.
About a month ago it was really cold here for about three days. I took a bucket with warm water out to my goats, they really enjoyed that. I think a nice drink of warm (not hot) water would be nice.
i guess also we should ask... do you have specific concerns (are they shivering? changes in behavior? are they currently goat-cicles?)..and how cold is "cold" for you?
for instance, is cold for you -30*, or just about freezing, or 40*? i cant tell what part of the country you are from.
when its really cold here - below zero with or without the windchill for us - we might give a SMALL handful of corn or sweet feed in addition to their grain ration.
but really your best defense is what everyone has said, and also:
* warmish water at least twice a day
* keep them out of the wind; use a tarp to wrap their shelter if its breezy inside
* bed them down deeply in fresh straw
* feed several times a day instead of just once; feed less at a time but, more often
* make sure they have enough hay - their working rumens will keep them warm
remember that livestock are better able to deal with cold than we are so unless you have cause for concern they are probably ok.
i would not change their diet...especially not with processed foods like quick oats.