Of course, we don't know when. But neither does he. This is a tricky business. By then he must make sure he has his job done (securing China's independence and its freedom from internal dividing forces), and the new amendment must be a well balanced and practical one.
"我將無我,不負人民" sounds like an accurate response to his removing the term limits. Apparently it is a self statement and a promise.
I chose to trust Xi.