Learning a familiar fiddle tune in a different octave, key, or position, is a great way to gain a deeper understanding of the tune and fretboard layout. Playing Old Joe Clark in the lower octave with the bass strings will unlock a whole new world of sound and licks. If you're at a jam or in a band, it's really cool to play one break on the treble strings, and the next on the bass strings.
Sometimes, when playing melodies on the lower strings, the notes can sound kind of muffled. To really get these notes to "cut" in a jam, try picking closer to the bridge. This can create an undesirable tone on the treble strings, but it works great to make those bass notes really jump out.
There's a lot of great licks, and traditional fiddle tune variations to explore here. You can switch in one or two or switch in a bunch to create completely new arrangements of Old Joe Clark.