> what exactly am I supposed to do with the above?

Exactly what you did there: ask a question.

You tried it, you know where the potential failure points are. Don't assume the super optimistic person hasn't considered them. Ask them how they would address those issues. If they have addressed them, maybe there is something workable. If they haven't addressed those failure points, you have given them a choice: to tackle those issues in the background or to set the idea aside.