What @Strega said. Your Roku will just see it as the same network it previously connected to and reconnect on its own.
What model Roku player do you have? As long as it's not a Stick model, you can buy an inexpensive universal IR remote that supports Roku players. Many can be found for less than $10. However, if you have a Stick (models 3400, 3500, 3600, 38xx), they do not support IR, so you have to have a real Roku remote for them.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Ultra (4800), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.