Why not have "Seasonal Event Page" - as your first subheading have "Seasonal Event 2013" with a complete listing and information; underneath have "Recent Seasonal Events" for 2012, 2011 etc in less detail.
That way, you're adding to this page over time ( rather than just deleting pages that are x years old because you don't want your site getting too clunky - in which case there will be broken links floating around the internet) - and the reader gets to look back at some info on previous years without having to delve back into the archives.
The only problem I can see is that - if someone follows a link to "Seasonal Event 2008" expecting to get lots of details about this event in 2008 and they actually only get a brief summary, then - is this -possibly? deception/grey hat??? In my personal view, it's better for them to get a brief summary than a deleted page.