"The kindness of strangers" is a quote from the Tennessee Williams play "A Streetcar Named Desire". Blanche Dubois, the heroine of sorts of the play, says, "I have always depended on the kindness of strangers," hinting at her past as a prostitute. The play was turned into a movie directed by Elia Kazan, the grandfather of Zoe Kazan, who plays Clara in this movie.
Although the film implies that the family lives in a small town within a manageable distance outside of Manhattan, the husband's Police jacket tells us he works in Buffalo. That is over 372 miles, and well over a 6 hour drive.