I used fallen leaves as "bedding" in the run..............just liked it underfoot when it was really cold and messy in the run last year. ice then melt then mud then frozen mud then snow..............repeat ..............add leaves on top and it seemed helpful.
Cloud is doing a good job 
if you check out the "poop" chart in my signature..it will show you an array of chicken do-do's yes, it is gross..it's poop...it is amazing what we get used to . Just sound s like some of the normal stuff, BUT..use the chart as a helpful reference...
**as far as the coop...5 months - young, but i know 2 of mine(marans)- aren't too much older(6) and are doing fine in these temps, as long as everyone is feathered-in....you have to watch where that air is hitting them,it shouldn't be... you do not want them in direct 'air-flow-drafts'....i know some on here have even used old empty feed bags to cover he outside of their coops to help eliminate drafts, maybe there are some examples-pics ,...if their roosts are lower, then make sure the draft/air flow is higher ( ventilation)...the hotter/moister air will be naturally at the top..you want that to be able to leave the coop, so as not too effect them, combs could frost bite..or worse, depending on the draft and moist air left inside the coop.
It will be cool/cold in there..but very livable..mine are happy they are all closed in now and out of all the possible- wind.
**Fermented feed....there are many different ways to do it, but it all benefits them and you..i use less feed and there is no-waste.
my method..one bucket, one plastic scoop with drain holes..(never use metal anything for this, it will have a reaction to the vinegar)...UN ppasteurizedApple Cider Vinegar-(ACV) it will say on the bottle that it has "mother"..that is what you want!..I started mine with 2 scoops of dry layer feed , then i poured a "glug" of AVC into it, gave it a mix..then covered with water...doesn't have to be hot...but this bucket should be in a warmer place..not sitting outside, so that it can do it's "magic".....some people have their stuff outside..i would think that would be more like "soaked" feed rather than fermented...but, i am not an expert..anyway, if you won't mind the smell, some people are sensitive,...ahem..DH.,..you can keep it in your house-basement..anywhere not outside to start..give it a sitr once a day..should only take about 2 days for it to start to bubble..yes..bubble..it's cool...then it is ready..scoop a plop out and feed..now sometimes they go for it sometimes they look at it like you just scraped it off the road..so..eventually they will eat it if it is all they have..just like kids....
When you take a plop out, you put back into this bucket a scoop of dry feed, stir, and just enough water to cover..done. next morning you should have a nice.."muffin" of feed on the top. Scoop that off..feed it to your birds..then again add a scoop(1cup) to your bucket, stir, water to cover..done.....
Now, then amounts vary depending on how many birds you have...but i think in general it goes , what...1/2cup feed per bird....that might not seem like a lot, but the feed been blown-up and soaked in ACV which makes it a lot more digestible, the nutrients will absorb much better into their system than dry feed alone, plus it is wet/soaked..fills them faster.
I hope i did not confuse you, i have a tendency to blabber on ...any question to this..i am sure someone here will fill in my gaps....and have other options...
