You can create a local mirror of CPAN with minicpan
. It's intended to distribute a copy of CPAN (or a subset of it) on media so you have it in case there is no internet available, e.g. a USB drive that you can use on a laptop while you are on an airplane so you can still install a dependency, even if it's outdated a bit.
Check out CPAN::Mini and the minicpan utility on CPAN as well as this guide on how to set up a mirror on perl.org. There is a guide on blogs.perl.org as well. Furthermore, this guide in German is very comprehensive and has a list of related material at the bottom.
In fact, there is a whole tag minicpan here on Stack Overflow. One of the very helpful reads (though not a full duplicate) is ysth's answer here.