I just looked at <http://wiki.documentfoundation.org/File:LibreOffice_Tri-fold_Reference.odt>, and it showed me content not fitting properly on pages that were 8.5 × 11 inches with 0.79 inch margins.
The page size is not set to A4, but apparently tries to use the default styles of whoever opens the file. I don't know how to control that, but I would like to know. A document with a careful layout like that should have its paper and margins recorded along with the content! Auto-layout would make more sense for "flowing" material, but even then I think it deserves a warning, like when updating a template.