Custom page with blank staves

[Ivanov Dmitry]

I am working with piano teacher upon solving the harmonization
exercises. To solve them I need a blank sheet with music staves
grouped by 2 with treble and bass clefs.

Usually one exercise requires 2 sets of staves (4 staves totally). So
far I was able to use this code from the template
(https://lsr.di.unimi.it/LSR/Snippet?id=663). I created an ideal image
of what I want. But I am not sure that there will be enough space on
the page to contain 8 pairs of staves if we add extra space.

Can someone help me with adjusting the code?

\version "2.22.1"
#(set-global-staff-size 20)
\header{
  tagline = ""
}
\score {
  \new PianoStaff <<
      \new Staff {
        \repeat unfold 8 { s1 \break } }
      \new Staff { \clef bass \repeat unfold 8 { s1 \break } }
    >>
  \layout {
    indent = 0\in
    \context {
      \Staff
      \remove "Time_signature_engraver"
    }
    \context {
      \Score
      \remove "Bar_number_engraver"
    }
  }
}

% uncomment these lines for "A4" size
\paper {
  #(set-paper-size "a4")
  ragged-last-bottom = ##f
  line-width = 180
  left-margin = 15
  bottom-margin = 11\mm
  top-margin = 12\mm
}