Not at all tricky. Have to look at it from 2 points of view. As a consequentionalist, and as a deontologist (focuses on intent). consequentially, all signs favor the morality of euthanasia. the money saved, the pain and suffering saved, and the long term emotional benefits on the family are all major wins for euthanasia.
if we focus on intent, then we ask, is suffering good? When is pain and misery a preferable option? If the patient will die anyway, why not put their fate into their own hands?
As far as sudden recoveries or unexpected extension of life past an assigned death estimate, how often does that happen? those things are miracles, or what we call miraculous. if we practiced non euthanasia as a rule because patients were waiting for some highly unlikely miracle, that is morally wrong