Sit on LH (just kidding)
1- LH up an octave. May still be playing the bass line, but at least it's not in the bass player's range.
2- "power" Fifths (like C+G for a C chord). Still up.
3- Lots of Gospel + Jazz keyboard players use LH tritones (like E+Bb for a C7 chord). Since these are rootless voicings in the Tenor range around Middle C, they give plenty of room for the bass to do its thing. May be a bit more complicated to learn, but well worth the effort.
Of course, the RH may have to shift up, too...