Yes I'm well behind on this programme, somewhere in series 5, so please no spoilers.
But...

If that all kicked off in real life in the UK, where would you try to go?
We wouldn't have nearly as many firearms as they do on the show, or as many wild animals to hunt.

I think i might try to head to Caerphilly castle. Strong enough walls to keep the walkers out, and decent line of sight to look for attackers

Alternatively somewhere like steep/flat Holm would be pretty good.