Watching S3 and wondered have the now set the show in USA and no longer uk?
Having only watched the first 3 episodes I can confirm that only the first episode is set in the US, not sure about the ones after that.
i don't think they're tying it down to any one country.
I think that now Netflix is financing it, they are trying to broaden its appeal for the US market.
Though many British programmes are popular in America. I think Brooker used the higher Netflix budget to expand the scope of the series.