Yeah, knowing he's only got so much time might just ruin his strategic planning with impatience. It seems like the moment is his though. There are a lot of houses in Westeros whose sympathies were always with the Targaryens, and who are sick to death of the Tyrell/Lannister alliance. With Kevan's death and Aegon's resurrection it would seem like Connington has just enough momentum to reclaim the throne for the Targs.