You've probably heard that cacao can't really survive cold very well. While that's probably true to some extent, the numbers I keep seeing seem to be more of an overall guideline for yearly temperatures. The range typically says 50-90 degrees. Lower than 50 is said to damage the trees while above 90 is said to prevent growth.
We went out of town and left several cacao trees on the patio thinking it wouldn't get very cold while we were gone. I was surprised to see the weather app say it got to 45 one evening and there was no way I was going to get back to it. Fortunately the plants were fine. One new leaf on one of the trees did have some damage but all of the rest of the trees and leaves seemed to have no adverse effects. I come to the conclusion that I need a reliable gauge to see when I need to worry. If the trees really can do just fine in 40 degree weather (just without new growth coming in) then that is something I would really like to know.
After doing some research, it seems like cacao trees can indeed survive much colder temperatures. I wouldn't make it a habit but even where it grows naturally, southern Mexico, it can drop even into the thirties occasionally. This is by far not the normal temperature but it just shows that even temperatures below 40 won't necessarily kill your cacao tree. I, of course, want the trees to grow well so I think I'll just keep my trees inside.