For the elderly (especially those with dementia), being able to watch TV independently is a challenge. One thing you can do to help is make the remote easier to use by minimizing unnecessary choices. When my mother first started having difficulty using the remote, I marked and color coded the buttons she needed. Then as her dementia progressed, I made cardboard cutouts and used painters tape (which sticks and re-sticks without residue) to affix them to the remote control. The very last thing I did was the superglue a fat plastic bead to the PLAY button for easy recognition.
Note: I had attempted to put photos here, but that did not work.