CBS won't put up with demos like that. If it carries on like that, they will do with what they did The Millers. Cancel it and shut production down immediatley, or at least once they finish production with whatever episode they are filming. Although even The Millers never hit those demo's.
The Good Wife has had poor demo's for the last two years. The excuse for it's renewals has been the acclaim and emmy nominations, but that excuse can only go so far. Especially as it was a huge flop in syndication and was taken off in less than 2 months. I would expect a final season confirmation in months to come. Although i originally thought it would be given a short final season like The Mentalist.