I think that most of us probably have some idea of where our “line” is (meaning what we think we could live with), but no one can truly know until they’re faced with it, and not everyone has to make the same decision about what that means for them.
I still need to formally write up my advance directive because I’m a relatively young person in a fairly dangerous sport and we should all really have that documentation in place, but my parents know what I consider to be my line right now. If I suffer severe brain trauma that significantly impacts my cognition regarding my identity, I don’t want them to keep “me” (my body) alive, because I’m not me without my mind. I have no idea where I would settle regarding partial or total paralysis because I haven’t lived it, but I’m not going to judge anyone else for the decision they make either.
Two things can be true at once: there are a lot of places in the world where people with disabilities are not provided the support and resources that they should have and deserve which is something that we should all be angry about and be trying to change, and Caroline should be able to make the decision that she felt was right for her without being judged for it.
We say it all the time in threads about euthanizing our pets and our horses: there are worse things than dying. Only we can decide for ourselves what those “worse things” are for us.