I've a West Yorkshire accent and have kept it throughout my life, in 4 different countries, Southern England, Austria, NZ and Australia. These days I use Aussie phrases too, just to confuse things.
Mum was born in Liverpool but at age 9 she ended up in a boarding school with Southern kids, and picked up some of their slang, so I have a few other English influences mixed up with the dominant Yorkshire.
I'm married to a Batley man, so there are few influences against retaining my beloved dialect. Anyway, when I started learning German at age 14 I found quite a few dialect words in standard German, which intrigued me. Oh, and my flat Yorkshire vowels has always been an immense help in the German language (alas, more of a hindrance with French).