A close family member with United States citizenship has been staying in the Netherlands with us beginning in August, and would like to stay on until December. This would result in him overstaying his Schengen tourist visa by about 20 days (he has been outside the Schengen area in the meantime)

1. What are the chances this would be a "problem" when departing from AMS? If it were a "problem" then what are the consequences?

2. Do you have any recommendations for otherwise extending the visa? We thought about either officially applying for residency (and then simply cancelling the process). Or apply for an extension based on Article 8 ECHR (to lead family/personal life).