We have a “go bag” packed in our house. In case of emergency it has water, a torch, change of clothes and so on all packed and ready.
What if you woke up late on viva day? What if you needed to get to your viva quickly?? What would be in your viva go bag???
Three things: your thesis, annotated to your heart’s content; pen and paper, so that you can make notes; water, because talking about research is thirsty work.
Those are the essentials; you can pack more if you need. What’s in your viva day kit?