We live on a hill with houses only on one side of the street and a lot of open area. Over 25 years we’ve had years with few to no trick-or-treaters. When our kids were little we were one of the few families with children. They would go to neighbors we knew (especially the ones handing out full sized candy bars 
) then head down to friends’ neighborhoods with flat streets and more families with kids.
This year we had more that ever. Still under 20, as this is a high-effort low-reward area. Told H to be generous! A sign that the neighborhood is changing. Now we’re the “old folks.”