Hello DaisyRyder, it is at times a matter of preference..some like to keep them very tightly growing like that...while some like me, prefer to have one good specimen per container as I have them here too and they do grow into a good sizable tree with lots of branching, so it is really going to be a tighter growth if kept too crowded.
So while it is still easier to separate them, I would do it now. So if it were mine, I would just separate them carefully, some roots will be disturbed/damagedfor sure, such happens during repot time, but it will just grow new ones eventually, and put it in better well draining media, mixing in lots of pumice or perlite with the soil, so it can stay much longer in the container safely, making sure container has drainage holes. You may have to stake the plant for awhile as it acclimates to the new set-up.
I leave my Jades outdoors year round here, and we also get the occasional 20F but it endures. It will get some cold damage but it bounces back well once warm weather returns. I always find early Spring or early Fall a good time to repot it, it actively grows more on my side when temps are cooler.
