Prof. Alan Jacobs, who I quoted in the first card above, seems to be of this kind.
Based vaguely on impressions from his writings, I understand C.S. Lewis to have been of this kind also.
At one point, during a time when I still laid great emphasis on mystical experience as integral to the event of salvation, I had a pet half-serious hypothesis: that if C. S. Lewis was in fact “saved,” then no other person in history was ever saved.
This obvious absurdity was my way of expressing my confusion at the time: Lewis's conversion seemed (and still seems) to have been thoroughly genuine, but it also relied on an esoteric and intellectual chain of understanding that remains wholly incomprehensible to most Christians at most times in history. If he was in fact saved, I reasoned (not well, I admit) then perhaps conversion depends on logical understanding more than anything else; and if so, how do I know Lewis's understanding wasn't the truest and deepest possible, or even the only correct one? If so, Lewis and perhaps a handful of others were the only people ever saved in all of history.