After many years of working in this area I still think survive is the best verb to associate with the viva.
Manage to keep going in difficult circumstances.
Survive doesn’t mean it’s going to be a struggle, but it doesn’t mean it won’t be hard.
Difficult is different for everyone. Manage might be harder or easier. Survive doesn’t come automatically.
The difficulty of the viva might be found in different things for different people.
Survive doesn’t mean you might not thrive in the viva. Survive doesn’t mean you will be scarred by the experience. Survive has a positive aspect for you: whatever the difficulty, whatever you did, you kept going.
Surviving doesn’t automatically mean the circumstances were bad. They were difficult. They were a challenge.
Not so great that you could not keep going.