My father-in-law is caregiver to my mother-in-law

My step mother-in-law has previously been diagnosed with terminal cancer. Throughout this excruciating process my father-in-law is her caregiver and has been as attentive as any one person is capable of. My father-in-law is also a very poor communicator whom has zero experience aiding any serious illness let alone a most beloved individual with terminal cancer. With this we (meaning his children and his wife's children; all of which are adults) are being held at a distance and are only allowed to communicate with himself at times he chooses. This means, no visitation throughout this process, no calling unless he reaches out, no cards, no communication. In part, this is due to his desperation and inexperience at managing with his grief through this process. In part, this is his desperation and inexperience at aiding the sick. And in part, it is him doing what any of us would be trying to do, our best. He is legitimately concerned that any of these things, outside of phone calls, present too much risk of carrying a contaminated virus. He is scared and is at the end of his rope. In all of this he is understandably angry. Angry at everything and everyone. Angry at well-wishes (who wouldn't be) and all of the niceties that people attempt to extend during these times. Angry at all of their children for not spending more time with them. Angry hearing about the lives of their grand children and how well they are doing. Angry that life around them gets to carry on. Angry at the doctors. Angry at the cancer and what it is doing to his wife. And in his own head - I am sure angry at his wife - as unreasanable as that may be.

He is also at an extreme loss. Having expressed his own depression as wanting to end his life after my mother-in-law succumbs to this cancer. I read that this is a common sentiment and that while it should be addressed professionally should also be understood as a not-uncommon desire amongst caregiving spouses. I read that this anger that I have explained is common too. Among the caregiver as well as the terminally-ill. I understand that space is needed and that many of the concerns that he is expressing are at least in part, valid.

What I am hoping for is some insight. Insight into how one might be proactive, given what I have written, in aiding to his needs while he is tending to our mother-in-law's needs? Whether this is being even more understanding, giving more space, doing nothing or being more diligent.

A COUPLE OF NOTES: I myself have grown under a roof where both parents worked in hospitals caring for the sick. My mother in particular has much experience with end-of-life caregiving that was in part imprinted onto me via lived experience. However, in this case hospice will not be considered by either in-law. Nor will they let someone as personal as my mother visit them to provide assistance. Again, my father-in-law is absolutely unwilling to let anyone in on almost any level. Add to this that their residence is 9 hours away from our location and further for some of their other children.

Thank you.