Furthest small city from London is Dunedin NZ
Furthest large city (over100,000) is Auckland NZ
Furthest Capital city is Wellington NZ
I've been to all of them many times via many places & there in one direction and back the other sometimes.
It's France I'm really missing though. I usually go for a long trip in summer. I didn't go last year - I barely left the house! I won't be going this year either. 😢