File Manager management

My District (District 24, www.d24tm.org/ ) has been using File Manager for about 5 years years to store District documents (minutes, award info, etc).  This type of storage likely started when our District DropBox account exceeded the "free" threshold.  The File Manager is also holding 20 years of Newsletters as well as many years of membership lists that need to be culled. While we have named archived folders with an 'x' so that they are at the bottom of the listing, I want to review other approaches, including vendors, to house our required and desired documentation.  Is there an efficient way, short of downloading files one-by-one to my computer, to move these to another platform product? Is there a more efficient process to save these files off instead of downloading each of them one-by-one?  Thank you. 

Sorry no, file by file.
FTH file manage was never designed to hold large quantities of files.