The best way to handle it, IMO, is to have Leia’s role fade away naturally into the background due to all the other things going on. Then, have her show up again at the end of IX.
I really hope they don’t kill Leia. There’s no way to do that tastefully now. And it’s not like she needs to be at the forefront of the story.
Well, now that someone’s brought it up …
Episode VII was always supposed to focus on the new characters. By all accounts, our OT heroes had little more than cameos in Arndt’s draft before Abrams decided to give them a bigger role. He barely even got to Luke after touting TFA as the OT gang’s last hurrah. False advertising if ever there was any.
So yeah, it sucks that they won’t be able to seamlessly bring Leia’s part of the story to a close, but I have to imagine they had a contingency plan in place for a situation like this. At least Carrie still gets to stay in IX.