Looking for remote logging solution

Hi, I'm trying to find a solution to help my elderly dad who lives 100 miles away, he can view simple apps on a tablet but is very untech savvy with muscular difficulty typing and using mouse/trackpad, basically I'm looking for the easiest way to stick a MiniPCstick /Pi4 or some other cheap computer into a HDMI input of his tv that's always active and logged on that I can control from my windows pcs (but if raspberry pi is only option I can get one here too) to help him browse and shop etc. He would have trouble logging on his end so the solution his end would always need to be open, bit like google chrome remote desktop. thx