Just to mention it: This OS you have “Win 10/64” allow not only to display nice icons or previews of files. You can sort the view in explorer according to your needs. Either click on the column headers to sort by date/name etc. or use the context menu of the folder (find a spot where you can right click on the folders background or you will get the menu for a file).
If you need the illusion of being inside LibreOffice: Use the open-dialogue and perhaps resize it as big as you may need. Got to %APPDATA% or where your backup folder is. The dialogue allows you the same interaction as an explorer-window outside of LibreOffice (including delete)
But remember to leave the dialogue with “cancel” or LO will try to open the last file you clicked on.
IMHO LibreOffice checks the contents of the file it gets and will give it to the appropiate component (if it has one), but I did not test this.
Appending .bak is an easy system, but it gives an "unusable" extension, as the file may contain different formats. You'd need a "bak-open"-Tool, to pass the file or a temporary copy to the software responsible for the extension to the left of .bak.