My ticket is restricted to a specific train (i.e. saver fare). Can I catch another train if demand is high in mine?

Your ticket remains restriction to a specific train. This means that you cannot catch another train with it.

We recommend booking early. This way, you will probably be able to select the seat you want. Demand can change, and if lots of people want to take a specific train, you might not be able to reserve a seat after a certain point. We therefore recommend booking as soon as possible.