The wolf packs on Isle Royale used to be the paradigm for a successful natural system. I studied them when I was in college. But that was forty years ago. Sic transit gloria mundi. That applies to wolves as well as humans. Today the pack is inbred and declining. It is still a great study of a natural system. A healthy wolf population is just not naturally sustainable. Maybe more correctly, it is episodic. Wolves move in and then die off.
Isle Royale is an island w/o sufficient size or diversity to support a healthy population forever. The current wolf population arrived years ago when Lake Superior froze hard enough that they could cross. (Interestingly, this year it was cold enough for the first time in a long time so scientists could see the real conditions.)
Isolated populations tend to become weak and die out. I posted an article below about wholly mammoth die out, where some of the same inbreeding was happening. We have human cases.
I recall reading about Finders Island, near Tasmania. It was colonized by humans in the deep past and then they became isolated. Gradually, aspects of their technical culture were not passed along and they regressed to a primitive, inbred society that just died out about 4500 years ago.
A better documented case, although for different causes, was the Norse colonization of Greenland. The Norse colonized the place when it was warmer, about the year 1000. It was uninhabited by people at the time (Inuit had not yet arrived) and there was grass and resources to support two colonies. As the climate became much cooler over the next centuries, connections were lost, until the last people just died out.
Anyway, it is likely that human management, i.e. bringing in more genetic diversity, can sustain the wolf packs. Park officials take the hands-off approach. I suppose there is a “prime directive” type problem of humans managing nature. That means watch the packs die out and wait for them to others to arrive by random chance. It works in the long run, if you have thousands of years to wait. When new wolves arrive in their new world, it is like heaven for them, with lots of moose and other animals to eat. The populations grow rapidly, but not sustainability.
Reference article from Science Magazine – http://www.sciencemagazinedigital.org/sciencemagazine/24_april_2015?sub_id=CfjvGuIE7FnHW&folio=383#pg15