I would like to use CPAN::Mini::NoLargeFiles, however it doesn't seem to operate correctly at all.
It relies on LWP::UserAgent::Patch::FilterMirrorMaxSize to do the dirty work. Maybe that's the part that's not working?
I wonder if LWP::UserAgent::max_size() could get the job done?
It is true, however, that you can run this each time, to free up some space — find -size +10M -exec rm {} \;