I could imagine a series on the Isle of Man or at Gibraltar.

Heck, imagine a zombie apocalypse in somewhere mountainous and remote like at an Army outpost in the Kunar Province of Afghanistan. That's a part of the Hindu Kush mountains, an extension of the Himalayas. Think about all the chaos they would be going through just trying to keep sane there. Definitely no easy access to helicopters or planes, and roads for trucks are not for moving quickly from one place to another.