I figured performance would be sluggish. 
This isn't a regular production run. We are moving data to a new system and would like to clean some stuff up. The legacy systems did not account for non USA based addresses so a lot of them are buggered up with city in the address line and country in the state or zip code line. 
Performance is not an issue. It is being run on a non prod server and if it takes a week to run that is fine.