I've got 6 memberships in my extended family which were taken out before the season started.
When these tickets went on sale, only 4 had booking history this season , so i could only book 4 tickets.
When the few remaining tickets went on sale for members without booking history, i had to ring the ticket office, change my tickets to somewhere near the back row of the Trinity and at the same time log in online and book 2 extra tickets next to the 4 tickets being re-allocated.
A little stressful, but got 6 tickets in a row!