Oh I have.
There have been many times in the summers I've walked in 10 minutes before showtime and the outer sections are still completely empty and remained that way through the show.
Alas, that is anecdotal for both of us and not a constructive game to play on the internet.
I even saw that over the Xmas holidays. They were running 3 shows per night. 2nd show was walk-up right until showtime. 3rd show was half-full. Of course, it was freakishly cold all week, so that could have had an impact.