Staffs extending past the end of music

[Tyler Stank]

I'm writing a piece in verse/refrain form, in which the verse is a single
singer ("Cantor") and a cello, while the refrain has SATB harmony as well. 
I'd like the line to break at the end of the refrain (this is accomplished
by \bar "||"\break) and cleanly end the SATB staves, but clefs and lines are
drawn on the next line, even though there is no music and they end before
the first barline.  I'm using barchecks and it compiles without warnings, so
I've ruled out having more music than fits in the measure, which is
sometimes responsible for a similar issue.  My question, then, is how do I
fix this?  Bonus points if I can still end the line and the staffs in the
middle of a measure.