I bought a Tracfone (Motorola W370) with "double minutes for life" about 18 months ago. Every 3 months I spend ~$20 to get another two hours (60 min, doubled to 120 min) or else the minutes expire. The phone works fine here in Central Texas, and I've had no problem using it during my travels to Cincinnati, Dallas, Los Angeles, Chicago, San Diego, and various other places. (No guarantees in Dry Gulch, Nevada.)
I do NOT text, access the Internet, watch videos, or use it as anything OTHER than a basic phone, though some of those capabilities are present. In other words, it does EXACTLY what I want it to do - I use it as a phone. Period.
The one disappointment - and a trivial one at that - is that you can't download ringtones except through Tracfone central, and they don't offer anything I want. (TracFone disabled connectivity through the mini-USB port, and strips sound files from emails sent to the phone. <expletive> )
If your 83 year old dad has sharp enough vision to see the buttons, and enough manual dexterity to use them, it's worth considering.