You said they live in the garage? Is there power to it? Maybe you can work with your neighbors to create a warm box with a light bulb or something. We did that, just with an old milk crate, a theromstat, some styrofoam, and a light bulb. (it was a long time ago, sorry I don't have any pics).

Whatever happens, I do think that every effort should be made to keep them together. Good luck.