We've had a talk and our plans are something along the lines of the following;
- Get rid of all old and out-dated content.
Instead of "Get rid of" how about "move down to a subdirectory called something like "old".
Then over the next thousand years this can be developed into subdirectories for each decade or century - at any rate, a new one each time the site is redesigned.
Our modern trend for "get rid of" causes so much landfill. Let's think of "preservation" instead. Today's boring records become interesting archives a century or two later.