It was not until May (1875) that the (Empire) club was able to definitely complete its nine and enter upon any engagements, it having been a much mooted question among the amateur clubs as to whether or not it was possible to maintain their organizations with two out and out professional teams in the city. Many amateur clubs disorganized but the Empire and a few others determined to hold fast for the season at least.-E.H. Tobias, writing in The Sporting News, February 8, 1896
The question of how long the Empire Club was able to "hold fast" is one that's still very much up in the air. It's certainly one that I would like to find the answer for. They certainly were still playing in 1876, according to Al Spink, but I've yet to find any reference to the dissolution of the Empires.