You will survive – manage to keep going in difficult circumstances – because you’ve done that throughout your PhD. You will most likely thrive too – grow, develop and be successful.
Prepare rather than perfect. You can get ready for the conversation you’ll have but you can’t be a paragon.
You can expect certain things will happen but you can’t assume that everything will play out that way.
You can respond to every question. You might not be able to answer every question.
Words matter. Verbs matter. Check that yours are right for how you think about the viva and how you engage with it when it’s your turn.