I fully understand the life/death mindset of JWs. I believed it, I taught it. I regret having taught it at all but especially to family.
When at death's door a few times myself, it was evident that my caring but indoctrinated JWs preferred that I die "faithful" than break an Org rule on allowed medical treatment.
Although next of kin may be a Witness, it is advisable to assign as health-care advocate one who will respect your wishes.
Sad but wiser . . .
CoCo