Fixer, these are questions you need to find the answers to through your OWN soul-searching, not vicariously through OURS. These questions you posed present a fantastic opportunity for everyone here to demonstrate how cruel and heartless they would be, and how magnanimous, compassionate, and gosh darn it, what an all around nice guy Fixer is. I think any reply given here that is more in line with Dirty Harry than Mother Theresa will be challenged by you with something along the lines of "but how could you be so cruel and uncaring?" or "how could you sleep at night?", etc.
What kind of answer do you really want to hear? What we think would be the RIGHT / MORALLY CORRECT thing to do, or what we would REALLY do if or when the morally correct thing to do is in conflict with our family's best interest (ie., surviving)? Because that's exactly what your question does in effect: it forces us to have to make a choice between the compassionate & PC thing to do (feed & provide for everyone), and the SMART thing to do, which would most ensure our family's continued survival (which the newcomers would clearly threaten by consuming supplies intended for your family, of which there may not be enough even for them).
I would argue that a man has a moral duty to HIS FAMILY FIRST. After that, the priorities break down as follows: AFTER the needs of his family are well and redundantly provided for, it is then (and ONLY then) propper (but not required) to provide charity to others in need. But a husband must remember that he took an oath in front of God (or at least in front of friends and witnesses) to protect and provide for his wife, and God intends us to honor that first and foremost before any charity is to be given to anyone else, including dear old mom. Furthermore, "the man who does not provide for his family is worse than an infidel." I would contend that for a husband/father to give the first red cent to charity or to a "brother in need" while his family has any lack whatsoever is evil. Yes, evil. If you as the husband and father won't put your wife and kids first, who the hell will? It is a duty to provide for one's family. It is a voluntary act of charity to give to others. So clearly, a man's moral obligation is to his family, NOT to a busload of unprepared freeloaders, whose fathers didn't take their own responsibilities seriously enough to provide for them, and who had just as much time to prepare as you did, but CHOSE not to, thereby CHOOSING whatever consequences go along with that choice, such as going hungry, wet, and cold.
Everything in life is a gamble; there is no sure thing. And there are always consequences to every decision, no matter how things end up. If you carried auto or home insurance all your life, and nothing ever happens, YOU are the big loser. It has nothing to do with right or wrong; you simply placed your chips on the wrong number when you rolled the dice. Similarly, the man who spends all his money on mundane preparations is the big loser in life if nothing ever happens, while his peers gambled CORRECTLY (at least financially speaking) by spending all their spare change on vacations, parties, weddings, RV's, jet skis, and bar tabs. Does the carefree, good-time rock&rolling grasshopper have any moral obligation to the eternally broke, ever-preparing ant if, toward the end of his life, no major disaster has happened? Has any society ever put any pressure on the grasshoppers to treat the ants to a vacation in the Hamptons once they're in their twilight years and no disasters have occured? Of course not. It was a gamble that the ants took when they decided to spend their money and efforts on preparations, when they could have been spending it on making their lives more enjoyable. As long as nothing happens, the ants are slowly and quietly paying the price for their choices little-by-little THROUGHOUT THEIR BORING LIVES. So spare us the false (and evil, for the above reasons) assumption that the ants owe it to the grasshoppers to deprive them--at the ants' expense--from the consequences of their own decisions/actions/life choices. Because if it doesn't work both ways, then it doesn't work.