The National Provincial Championship final is portrayed as to only be a few weeks after the start of the school year. The University of Otago school year actually begins in late February, while the NPC finals are held in late October - 8 months later.
The letter to Alex from his mother in Ettrick has the return address as "RD 1, Ettrick". Ettrick is not a valid postal town, and it isn't Rural Delivery 1 - the correct postal address for Ettrick and its rural surrounds is "RD 2, Roxburgh".