I like your proposed overview. However, it seems to be the exact same IMDb uses (which we are not allowed to copy-paste). Do you know if this overview was officially used by a proper distributor?

Yes, it is the same one IMDB uses. This was used on the official distributor site: https://www.searchlightpictures.com/demolition/

"Davis Mitchell (Jake Gyllenhaal), a successful investment banker, struggles after losing his wife in a tragic car crash. Despite pressure from his father in law, Phil (Chris Cooper), to pull it together, Davis continues to unravel. What starts as a complaint letter to a vending machine company turns into a series of letters revealing startling personal admissions. Davis’ letters catch the attention of customer service rep, Karen Mareno (Naomi Watts) and amidst emotional and financial burdens of her own, the two form an unlikely connection. With the help of Karen and her son, Chris (Judah Lewis), Davis starts to rebuild, beginning with the demolition of the life he once knew."

@kolvas said:

Yes, it is the same one IMDB uses.

We are not allowed to copy IMDB-exclusive overviews.

This was used on the official distributor site: https://www.searchlightpictures.com/demolition/ "Davis Mitchell (Jake Gyllenhaal), a successful investment banker, struggles after losing his wife in a tragic car crash. Despite pressure from his father in law, Phil (Chris Cooper), to pull it together, Davis continues to unravel. What starts as a complaint letter to a vending machine company turns into a series of letters revealing startling personal admissions. Davis’ letters catch the attention of customer service rep, Karen Mareno (Naomi Watts) and amidst emotional and financial burdens of her own, the two form an unlikely connection. With the help of Karen and her son, Chris (Judah Lewis), Davis starts to rebuild, beginning with the demolition of the life he once knew."

And this one is too long and goes against our overview guidelines,

I removed the "in Chicago" part of the current overview.