You should check out the Range Rover heading. One of the threads is all about how many miles does your Rover have. I'm currently at 167,000-ish with my 1990 RR County, and it's still going strong.
Also, "rebuilt" is such a vague term. If you mean a rebuilt engine, well, maintenance is the key to avoid that. If you mean "I have replaced every moving, non-moving, lubricated, should be lubricated, electrical and grounded part on the thing except the steering wheel at least once" then yes, you might have to rebuild it.