It's the greatest show I ever saw, but, no, it hasn't ever "worked"...meaning that despite my love for it in 1971, everyone I brought to it was left cold by it. (Except the bf you mentioned and my cousin Arlene, who was an art student.)
For decades, I treasured my memories of the original production and felt like I was the only one who loved it, then I came to BroadwayWorld and met others who loved it--and some who had memorized every moment of it through soundboards and videos.
Then the Paper Mill and the Kennedy Center revivals happened and lots of people loved it.
But, no, it doesn't "work" with an intermission, and it doesn't work without one.
It's still the greatest show I ever saw and probably the greatest show I'll ever see.