I doubt they'd go all the way to Konoha to get Karin. Suigetsu doesn't really like her; Juugo maybe might try to go get her but I don't see why unless he's secretly in love with her.
If anything I would assume they would just stumble upon the battlefield and there being a fight between Juugo vs. Kimmimaro, and Suigetsu vs. The Seven Swordsmen. Though I predicted the outcome of Juugo vs. Kimmimaro is Juugo winning with Talk no Jutsu and finally gaining control of his powers.
As for Suigetsu, he's going to have even more trouble getting the blades now that Kakashi and Killer Bee have the Executioners blade and Samehada(Unless he asks them nicely for it

), plus defeating the remaining edo swordsmen and the kid who hangs with the Mizukage will be difficult if he's going to be doing it alone. I just don't see Suigetsu succeeding at his dream unless he pulls a miracle jutsu out of his ass.