How do I list the next 7 days and any events (cpt) contained in those days

You should definitely do it in just a single query. then set up a simple loop, each iteration get that day’s date. then loop through all posts and compare the date to the date meta field, and output if it matches. I think something like this should work…

$today = date("o-m-d");
$future = strtotime ( '+6 days' , strtotime ( $today ) ) ;
$future = date ( 'o-m-d' , $future );
$event_query = new WP_Query(
    array( 
      'post_type'   => 'event',
      'meta_key'    => 'event-date',
      'orderby'     => 'meta_value',
      'order'       => 'asc',
      'meta_query'  => array(
         array(
          'key'     => 'event-date',
          'value'   => array($today,$future),
          'compare' => 'BETWEEN',
          'type'    => 'DATE'
        )
       )
      ) 
    );

for ($i=0; $i<7; $i++){
    $thedate = strtotime ( '+'.$i.' day' , strtotime ( $today ) ) ;
    $thedate = date ( 'o-m-d' , $thedate );
    echo $thedate;
    // loop thru all posts and check $thedate against your date meta
    // and output if it matches
    // then rewind_posts(); to set it up for the next day
}