Sorry, no solution. I am in a similar boat with my elderly father (94). He pretty much only watches one channel. When he had cable TV, he only had to push ONE BUTTON on the remote (the power button) and the TV came right on to the channel it was on when he last turned the TV off. Now he potentially has to push nine buttons in order to turn on the TV, get onto the Roku home page, navigate to the streaming app, and navigate within the app to his channel. I know, because I have written out step by step instructions for him but it is too much. He becomes frustrated and just gives up. Using the voice command to launch the streaming app only removes two of those button pushes but requires him to push the voice command button and speak which is too foreign a concept for him.
The experience of streaming has been nothing short of a nightmare for Dad. Now, he only watches TV if someone is around and able to turn it on for him. Has anyone figured out a way to help elderly users navigate this brave new world?