I agree with finding an interim place to get a reality check on how much work is involved in maintaining a rural property. That's before you add animals. We don't have animals but in summer we'd be overgrown completely without our riding mower. Also, how much isolation and seclusion would they be comfortable with? Having said that, living in the 'burbs is often the most isolating and lonely experience a human can have. At least out in the sticks you don't actually expect the 'roos to answer back.
I never thought of myself as a rural type of girl but our little plot of paradise is the only thing I'll miss when we leave to live in the U.S. I love the clean air, privacy, quiet. However, we both had to maintain p/t jobs in the city (and a p/t rental apt there) to maintain our rural lifestyle. I feel lucky we weren't trapped in the city 24/7.
I'd look at buying a few acres near a smaller, reasonably lively town. That way you have your rural lifestyle but can be near enough if you want company. I don't mean to be insulting, but if they're near retirement age they possibly need to consider being close to assistance in case of medical emergencies. My DH became very ill from a suspected tick bite, trust me you really feel alone out in the sticks when your otherwise healthy strong spouse gets sicker than you've ever seen them.
If you can buy or have access to an established farm, so much the better. Ours was built from scratch and after a few camping 'adventures' I would've been happy to never see the place again. But a few creature comforts (roof over head, shower, comfy bed) make all the difference. I'd never dismiss anything outright as a 'BAD' idea, better to at least have a try at it. Good luck to them!