MNRAS line wrapping in authors lists

In case anyone else using the MNRAS LaTeX class has been tearing their hair out inserting line breaks manually into long author (and institution) lists, using \newauthor, here's how I did it:

\author[J.~Bloggs et al.]
{\parbox{\textwidth}{J.~Bloggs,$^{1}$\thanks{E-mail: \texttt{j.bloggs@no.where}}
J.~Bloggs,$^{2,3}$
J.~Bloggs,$^{3}$
J.~Bloggs,$^{4}$
J.~Bloggs,$^{5}$
J.~Bloggs,$^{6}$
%...
J.~Bloggs$^{99}$ and
J.~Bloggs$^{100}$}\vspace{0.4cm}\
\parbox{\textwidth}{$^{1}$Department of Something, Somewhere\
$^{2}$Department of Something, Somewhere\
$^{3}$Department of Something, Somewhere\
$^{4}$Department of Something, Somewhere\
$^{5}$Department of Something, Somewhere\
$^{6}$Department of Something, Somewhere\
%...
$^{99}$Department of Something, Somewhere\
$^{100}$Department of Something, Somewhere}}

Next: a Python script to generate the above from a simple list of authors and affiliations.