Move \insertnavigation to the left in later sections in beamer footer [closed]

Question

I am inserting the list of section names in the footer using:

\vskip2pt\insertnavigation{\paperwidth}\vskip-2pt

The complete code for the footer (using the metropolis theme) is

\makeatletter
\setbeamertemplate{footline}{%
  \begin{beamercolorbox}[wd=\textwidth, sep=3ex]{footline}%
    \usebeamerfont{page number in head/foot}%
    \usebeamertemplate*{frame footer}
    \hfill%
    \usebeamertemplate*{frame numbering}
  \end{beamercolorbox}%

  \begin{beamercolorbox}[colsep=1.5pt]{upper separation line head}
  \end{beamercolorbox}
  \begin{beamercolorbox}{section in head/foot}
    \vskip2pt\insertnavigation{\paperwidth}\vskip-2pt
  \end{beamercolorbox}%
  \begin{beamercolorbox}[colsep=1.5pt]{lower separation line head}
  \end{beamercolorbox}
}
\makeatother

However I have too many sections and it escapes the end of the footer. See picture of slide:

To fix this I would like to move the navigation to the left as the current section increases. Something like:

\vskip-{\sectionnumber}pt\insertnavigation{\paperwidth}\vskip-2pt

where \sectionnumber is the number of the current section (made up the command).