Having never done this job (on any modern car), but appreciating access is difficult, how much of both pipes are visible once the trim is refitted? How much spare room around the two pipes is there once they exit the matrix?
Having struggled as you have, I would be tempted to visit a breakers, and see if you can salvage identical pipes from another car, either in one piece if the car is quite bare, or by cutting them. Sounds drastic, but with cut pieces of pipe, you may be able to more easily assemble them off the car into the matrix with the seals and clips, putting it back in situ, and then joining the two pieces on each pipe with a section of rubber hose held by (dare I say it
) - jubilee clips. The actual pressure in the system would not be an issue for joins of this type.
It all depends on how room there is, if there is space for joining hose pieces with clips, and the important bit - once cut there would be no going back.
That's why a visit to a breakers could be beneficial to experiment and assess it before you did anything further.
Like I say, I've never delved into that area on any modern car (never had cause to) so I am merely offering a possible alternative solution.
If you haven't already, for the time it takes, I think I would take the seat out just for easier access and manoeuverability.