I've been going to make a topic about this, but since a couple of them already exist - i'm just gonna comment at the latest one and hope devs will see this.
Now my first suggestion is more about this old Winter/Refrigeration topic, because as good as the game is right now already, it is still really disappointing (and especially so for the "late game" players) that in game food that's left outside in freezing cold is not refrigerated/preserved at all. I mean it's only fair that outside temperature should affect not only player and crops, but also food spoilage rate when you leave the food outside.
And so we come to the second part - which is ice (again there was an old topic on this). As of 41.65 water does not freeze at below 0 temperatures and there's no ice in the game.
I understand that freezing lakes or rivers would require quite a lot of mechanics changes and also wouldn't probably be that viable, at least until swimming/sailing is implemented, but water freezing in containers at below 0 is a must, as well as some ice mechanics, that allows you to use ice chunks/cubes as means of refrigeration in coolers or fridges without power.
And the winter conditions that help to preserve food - is not only a must, but an absolute necessity in the late game. I really hope that you would implement that at some point.
Also, to make it even more fair, your rain collector barrels should not work at below 0, right? Maybe not right away, but definitely after a couple of days at -5 to -10 any barrel of water should turn into a barrel of ice, which should make it unusable as a water source (at least until you warm it up).
I also must say, that i've been playin' this game since pre-alfa-before-steam times and it really has gone a loooong way - a big shout out to the devs; and also this ice-refrigeration thing may seem a bit trivial, BUT - since "power refrigeration" is in the game for a long time already and weather conditions affect other aspects of PZ life, and water freezing/vaporizing is one of the physical characteristics of the real world we use every day, it would only be fair to try and implement the ice and "non-power refrigeration" as part of PZ at this stage.
Really hope we'll see this at some point in the nearest future.