Has this been done before? Well here we go, just for fun!
Never mind whether or not you think it could be done, let's have some proposals for
how it may be made possible to do it.
Preferably without any major alterations to the story.
Here's one to start with:
Pick a handful of characters who feature large in it (Thingol and Finrod spring immediately to mind) and tell the bulk of the story from their perspective. The major drawback is that things might become
too depressing, but that aside I believe it could work.
Any others?