Automatically Query Parent Taxonomy

I have a custom taxonomy on my site that I query from the sidebar of the currently displayed term. Say I am on the Term X archives, then my custom post type of Products with the term of Term X are shown.

I would like to avoid an empty result so I would like to query up the chain until posts are found. For example:

• Term W (5 products)
  • Term X (1 product)
    • Term Y (0 products)
      • Term Z (0 products)

If I were to query Term Z then I would like to show the result from Term X and stop there.

Here is what I currently have, but I can only get it to go one level above.

<?php $queryvar = query_posts(array('post_type' => 'event',$the_taxonomy => $the_term,'showposts' => 10 ) ); ?>
<?php if(count($queryvar) < 1) {

do
{
$parents = get_ancestors( $term, $the_taxonomy );
$the_term = $parents[0];
$queryvar = query_posts(array('post_type' => 'event',$the_taxonomy => $the_term,'showposts' => 10 ) );
$term = get_term($the_term, $the_taxonomy);
echo $term->name;
}
while (count ($queryvar) == 0);
}
else { $the_term = get_term_by( 'slug', get_query_var( 'term' ), get_query_var( 'taxonomy' ) );
}?>