The plan continues to be "forever." We like it, it is in near new condition, it only has 57k miles, and a high end of ~$20k given condition and desirable rare options, it is still a fraction of anything that could replace it.
The only reason the thought of when to replace it is because
I saw a thread where many report catastrophic engine failures with replacement prices at twice the value of typical cars.
In our case, the LR4 is very low miles (57k @ 10.5 years) and I plan on preventively replacing all possible cooling system-related components. Similarly, I take good care of the engine and that should mitigate the possibility of chain-related destruction.
But on the other hand, the technology is getting dated and fuel economy sucks. I don't know that we will want to keep it beyond the time the kids are through with college. For now it fits a niche role and sees only 3-5k miles a year.
I guess the question is, should we entertain selling it and upgrading it in a couple of years or just roll the dice for 8+ years and if it blows up it blows up?