Currently the only way to change node locations is on a monitor-by-monitor basis. If we wanted all of our transactions to run from a new node, we have to change them all manually. There should be a...
While this can only be done in the platform at the account default level (once you manually change the location in a monitor from the default you can no longer do it in bulk for that monitor), the new JSON REST API does have the capability to change locations programmatically.