Well, we know the third-highest stacker is @ek with 3.3 million sats, which is a lot, but also nowhere close to a full BTC. It's possible one of the hidden top two has made it there, but I'm guessing it's pretty unlikely that anyone's achieved it yet.

And with only posting and replying (so not maintaining a profitable territory)? I'd imagine it's even less likely. So as to "how long," I think we're looking at multiple years at the most optimistic possibility.