I think framing it as "let them die", won't help. I frame it as everyone has the right to self determination. My mother in law died at 60 by starving herself to death for no good reason. We tried for years to help her. At some point, she as an adult, had the right to make her own choice. She checked herself into a nursing home and we let her go.  She convinced doctors that there was something else mysteriously wrong with her. Heart failure tends to happen when you don't eat.
The interesting thing about the left is they think people have the right to do drugs and want them to be supported, but think they also have to be saved from themselves, over and over and over again. At some point when all the information is out there, healthcare is out there. Medicine is out there, and people choose a stronger and stronger drug, knowing it will kill them, to get high and "escape" it's a choice that they must be allowed to make in a free society. 
I think that's a more productive way to frame it.