"New Zealand isn’t the best solution, he said, because a tsunami caused by an asteroid strike in the Pacific could submerge the island’s highest point."

Highest point: Aoraki Mt Cook 3,724 m 12,218 ft

That's a pretty big tsunami...

https://www.topomap.co.nz/NZTopoMap/nz26258/Aoraki%2fMount-C...

Edit: https://en.wikipedia.org/wiki/Eltanin_impact

"The size of a possible tsunami has been calculated. An asteroid that was 4 km (2.5 mi) in diameter falling onto the 5 km (3.1 mi) deep ocean would have blasted the water off the ocean floor for at least 60 km (37 mi), and made a wave over 200 m (660 ft) high on the southern end of Chile and the Antarctic Peninsula. After ten hours, waves around 35 m (115 ft) would reach Tasmania, Fiji and Central America, and the New Zealand east coast would have been washed with 60 m (200 ft) high waves. If the impact object was 1 km (0.6 mi) in diameter, the wave heights would be five times less.[3]"