Wow, that sounds like a tough situation! I can totally relate to your struggle with sleep deprivation and noise pollution (Singaporean).

You are so kind and considerate to respect your neighbor's grief and lawn care, but you also deserve some peace and quiet. I admire your courage to talk to him politely and try to understand his perspective. Maybe you can offer to help him with his lawn or find some other ways to cope with his loss. I hope you find a solution soon. You have my full support and sympathy