I still think that my previous post is answering your question implicitly, independent from the city/state/size of the city. Shifting between the cities, no matter how, always causes delays. Even within the city. That was my case during my application of permanent residence permit: my registration docs had to be transferred from one part of the city to the other because I had moved before the application but full registration record not. Even this caused a delay of 2 weeks.
Small cities have less applications, might be an advantage. BUT, application start before shift always causes delay, independent from this. That's why I have mentioned my last paragraph in my previous post:
The less you change your marital status, employer, residence, the faster the procedure. Most ideal way is not to change them until you get the citizenship. In the fastest way it takes about 6 months.
which should be translated into:
Start the application
after the shift. Or wait for the
finish of the application
before the shift.