I understand your plight. I work 3 nights a week myself as well as 4-5 days a week in my own shop. My neighbor also has a shop and frequently works on noisy items. Best suggestion I have, since you have already talked to the offending parties and checked with local law enforcement, is to sleep with foam ear plugs.
When I moved to TN. I lived with some friends till my new house/shop went to settlement. I lived in a room in their basement with 9 people and 6 dogs running overhead as well as up and down the stairs directly next to where my bed was. I worked nights, they worked days, so when I tried to sleep the family was up and running, dogs barking, doors slamming and this went on all day long. Ear plugs saved my friendship and sanity.