A master can definitely bounce an uncooperative larger opponent, skilled in taiji, a good distance. I have personally seen it. Kan shr rungyi, dzwo shr nan.
I have the same issue. But the reality is I don't (can't) push hands enough. Not enough partners, not enough time, not enough partners WITH time. (Don't you hate it when your job gets in the way of things that are really important?) But I think that reaching a high level in push hands is like reaching a high level in anything else. A lot of practice with a lot of different opponents, primarily those with better skill; and a lot of contemplation and research. There is no magic bullet. Also, I think if you become overly absorbed in trying to push someone a great distance, you will get worse, not better. Someday I would like to get to the point where it just happens - that is, instead of me doing push hands, push hands does me.
The following is from Kuo Lien-Ying's book, The T'ai Chi Boxing Chronicle:
"If your Push hands opponent does not have a high level of skill, then you will fall into bad habits. Get the best-qualified Push hands opponent in order to mutually refine and polish this art. Then you will move on to the higher level of the method. You must practice Push hands in accordance with the sphere of the T'ai chi boxing books or you should not push hands. You cannot get this from drawings or photos. If you try to learn Push hands from photos or an unqualified opponent, you will develop the defect of slipping hands, and the technique will not be effective."
I do not know what Kuo meant by slipping hands, but I get the gist of this. I also note through observation and experience that masters do not play around with hands, trying to gain good hand position. They connect centers immediately and gain control of the opponent's centerline (kind of like Wing Chun theory, but a different method). When they move, everything moves, including the opponent. A beautiful thing to see, even better to experience on the receiving end. As for being able to do it consistently? Somewhere, over the rainbow...