I saw your post before, but I didn't respond because I myself have lost hope on fixing a hoarding situation, though with other complications.

A couple of alternatives to CPS: you could try the county health department, or the police in your area might have a hoarding task force. Those generally only apply if the hoard is unsanitary, damages the home, or extends outside the home. Also, anything like that is likely to escalate any existing tensions. If you've already involved CPS, can I assume that there are some burned bridges with your daughter?

Hoarding is often associated with ADHD and OCD; are those present in your daughter or son-in-law? Sometimes treatment for comorbid issues can function as treatment for the hoarding. At the very least it can start them on a path to see things from a different perspective.

Grandparents here who live out of state. First time in our Daughter's house in 4 years. She has an 8 year old and a newborn. She and husband have always been hoarders and we should have stepped in more 8 years ago, but with the newborn we are in fear of the children's safety. Talking and offering supportive help has fallen on deaf ears. We are about to leave because we can no longer stay in a hotel and are not welcome in their home. Social services won't do anything because 8 year old is not physically harmed, she is fed and clean. I live in constant fear and my health is suffering. What can we do? Our Granddaughter has no friends, because no one can come in her home, therefore, she is invited no where and she is also exhibiting signs of hoarding. Btw- our Daughter is a LCSW of all things. Help!!!