This should answer some questions regarding WSS...
"Box-office business tends to decline across Broadway for several weeks after Labor Day; even so, Mr. Seller said that the production was expected to recoup its original multimillion-dollar investment and begin making ?a very nice profit? in the next three weeks. He added that advance ticket sales total more than $7 million. The musical, one of the biggest commercial successes now on Broadway, grossed $1.15 million for eight performances for the week ending Aug. 23; the weekly operating costs are approximately $600,000."
http://www.nytimes.com/2009/08/27/theater/27west.html?_r=1 So if they're already at the point of recouping really soon and have a nice advance, I don't see how the show is in trouble.
And Riedel mentioned that the production cost an initial $14 million.
http://www.nypost.com/p/entertainment/theater/west_side_substitutes_x8mwnhqva8DBuceCgSojGI