I've noticed in the past that I tend to accentuate my accent when I'm abroad. Having said that, I accommodated when I moved south, although I've still got some stubborn northern vowels - and, oddly, sometimes speak more like a Scouser than I ever did at thom.

I'm sad to think you won't come to the UK again, although I completely sympathize. Jetlag is horrible at the best of times, never mind with a sleeping disorder.