Changing IP subnets for Win2K domain

Due to company reorg I am told that the network addresses for our entire Win2K environment will be changing possibly overnight. While I can guess some of the steps to take with Site definitions and DNS, what other gotchas should I be looking at. I’m sure this has happened to someone before. My plan “was” to bring up the new network with ability to see old one, migrate to new DCs on new network, move member servers, and then take old DCs on old network down. I’m not sure I can do this if the change happens overnight. Thoughts? Good article links?