If you set the new router to have the exact same SSID and passphrase as the previous one, then the Roku should just connect. (Doing this just makes router changes more convenient in general, since you just change the info in one place and not on every Wi-Fi client device.)
Meanwhile, it would be a good idea to get a remote in case you want to change such things in the future. Phones only access Rokus, once they and the Roku are connected to the same network. An actual remote can communicate with the Roku even before it is connected.
Banned but back. Because why not?