I wouldn't risk it. If you don't repot it, the dirt/fertilizer could come out the bottom when you water (or overwater, as I do) or you might find there are little gaps between the rocks where you just can't cover because the stems are too close together. Plus, it's not that hard, and cutting any overgrown roots and putting it in a bigger pot can help the plant to grow in faster.
I repotted a pothos a few weeks ago and it's growing in really well.