Need solution for elderly

I completely understand your position and needs. My father has early stages of dementia and top that with his understanding of web technology being very limited which only added to confusion... streaming vs cable, buffering, channels and so on plus English is not his strongest of languages. 

So anyhow, what I ended up doing is deleting all apps/channels from the home screen.

Then I wrapped white tape around the buttons he had no use for and created a app/channel for him with the tv channels he wanted.

Named the app a name he was comfortable with and taught him how to press and hold the nic button while saying "Launch (the app name)" which would then launch the app.

I set a cookie saving the last tv stream he was watching from the previous session and had it load and play immediately.

I also programmed the video to stay full screen on launch and throughout, and only programmed the up and down buttons for keypress events, with up and down changing channels accordingly onFocus. Just like the tvs and remotes he was familiar with for decades., I created a overlay labellist which was visible based on keypresses ,I also prepended fake channel numbers right before each tv channel name ie.

1 ABC 

2 XYZ

I associated numbers to channels for familiarity reasons, which built confidence and really improved navigating and understanding the user interface and flow.

Anyhow if you need some help or code for the app I created, I will gladly help.