Location doesn't matter that much, it's all flavor text anyway. For example, you know a lot about Seattle since you've run many games there. Change all the names, call it anything other than Seattle, and BOOM you're playing in a new city.
All you need is the major backdrop to be there for it to be believable. For example, Seattle has the city-state surrounded by Amerind nations, San Francisco is the Japanacorp city, LA is half under water, Chicago has the containment zone (which was torn down I think?), Denver is like Seattle a bit, with the different countries and zones bordering each other, etc. Then you hit Europe, you've got Tir Na Nog, England, and Germany. From what I recall Berlin is similar to Seattle in that they have a security zone and a free zone (i.e. downtown Seattle, and the barrens).