I heard back from Kris and Kyle Espeleta (one of the producers.) I sent the questions via the Donald Cried website contact page, so I don't have a copy of all the questions I sent. But one was about who Tom Luke was (the film was dedicated to him in the credits). Kris wrote,
"Tom Luke is my beloved uncle who passed away right before the film was made. I believe he was in some way responsible for all the snow given to us during production."
For anyone else for whom the characters in the movie were like real people you felt you knew, and about whom you still have lots of questions, here's an April 7, 2016 interview Kyle shared with me of Kris and others at the Film Society of Lincoln Center that addresses some of those questions.