This question is one of the reasons reading the forum is beneficial to me during the stage of our adoption journey that we're in right now. To be honest, my initial response is different than my response after thinking about this question. I knew there were things we were open to in terms of alcohol, drugs, and minor challenges, but when I think about this question, those things almost seem like I've been asked "what is your preference?" or "what is optimal?" in an adoptive situation, not what could we "handle."
It's a tough question all-around to know how anyone might handle the situation if presented with it... because most times in life, what we think we want most definitely isn't always what God urges our heart to do.