I have used a machete a lot in the cold, typically in the teens. Against popular opinion, I think I would RATHER have one in the cold than a knife, and here's why.
As I understand it, the problem with the cold is that it let's the steel change state slightly. There are terms for what happens, but basically, it lets a steel that was just fine become more brittle. That brittleness will stay even after the steel is warmer, as it is a physical change in the steel. That change is why people cryo treat tools, so as to complete the processes that may have a hard time normally.
This change will affect some steels more than others. Typically, the harder a steel is to heat treat properly, the more likely it is that the cold will affect it. Now that that's out of the way, here is my ASSUMPTION on machetes.
Because of their role, and cost, most machetes tend to be made with a low carbon steel. This keeps the steel from fracturing rather than simply deforming. Also, the heat treat tends to keep the tool at a spring hardness more so than a knife hardness. What this means is that there is less potential for change in the tool, due to lower carbon, and when that change happens, it is less likely to bring the hardness to a point where it will result in the blade becoming so brittle it is likely to break.
This is how I view machetes, but it does include some assumptions. If you can show me for a fact that some of this is wrong, please do, as it is important to me as well.