I like to give a young Cephalotus plenty of room to grow and divide, and often start with a single plant in a 16" x 16" x 6" translucent plastic box. They typically send out underground runners (stolon), that will shoot up young plants. In time there can be enough material to pot up as individual plants. One of the challenges with Cephalotus, and in fact many Carnivorous Plants, is that they do not like their roots disturbed. When they get up to size to separate, I'll be sure that the soil is moist enough so that, when disturbed it stays together without falling apart, not so dry that it crumbles apart, and not so wet that it slumps away from the roots. I use a pot in which they will be repotted into, as a measure of what soil to remain, and what soil to keep intact around the roots.
I carefully remove the excess soil, and often do this for each of several of the plants that may have grown from the original source plant. I may have to use the future pot several times to help judge the amount of soil to remove.
I take care to insure the size of the soil ball will be the right size to fit into the pot. Here's where having the right moisture level helps keep the soil ball together. Finally the whole thing is carefully lowered into the pot. I may then tap the bottom of the pot vigorously to be sure the soil ball is seated fully into the pot. Done carefully, the Cephalotus will hardly "know" it was removed from its propagation container. Now keep in mind that this same procedure can work with many different Carnivorous Plants. Give it a try, and good growing!