The important thing is to not overthink it. It they have good shelter they'll be okay. I let mine out all of those days and they were fine. I wouldn't want them out there in the 20s with wind and puddles, but that's not usually a problem until late winter or if there's a strong cold front. I've let them free range in the evening in light snow, 10s with little wind, ice packs, etc. Some won't touch the snow, others walk through it. Some come out when it's 15F and others say "no way" and stay in the run.
I'd be careful about washing them in the winter. If they have protection from the rain/drizzle they'll go back under when they've had enough precip. Their outer feathers keep them dry really well. But if you get those down underside feathers wet that's when you can be dealing with hypothermia. So wet/dirty feet I don't worry about. They sit on their feet on the roosts anyway which will keep their feet warm and able to dry. Any poopy butts I leave alone in the winter...in the warm season sometimes I'll wet them and try to pull it off.
I worried about a lot of things my first winter as well. Someday you'll look back and laugh at some of the things you worried about. Now that doesn't mean I'm cheering the cold on...lol. They're a lot easier to care for in a tame winter. They survive fine in deep winter, but obviously they're not thriving.
Good luck and feel free to ask me anything anytime.