So, your "solution" is not to even take the farm idea seriously. Issue "settled". Haha.
What IF your dad would indeed spend some of his advanced years on a farm, "raise cattle, plant corn", whatever. You think it's an impossible illusion?
This is the same, lame thinking as saying 'free' tuition is "impossible", or ANY change to the current abhorrent system is "impossible"...so let's just stamp it all as an "Illusion" and not even pursue it.
Sorry, this is *extremely* lame, and I actually envy your dad that he (unlike you) actually has a dream or the motivation to do something, even if it seemingly goes against "common sense". Pursuing a seemingly "impossible" goal/dream I consider better than voluntary self-limitation. Aka: You won't see whether something works without trying it.