Finder uses spaces and sub-spaces to organize our information. An alternative or a complementarity would be the use of TIME to organize our information. Here is a video presentation : hipSpace
Edit: ok, I am the developer of hipSpace, but my app really answers to that question. Just "Save as…" your files in the "hipSpace" folder, that all ! When there are too much files in the space, Release them. It will be easy to retrieve them using the Time navigation (rather than the space navigation of the Finder).