My parents did this when their eldest dog died about 5 years ago. The younger one was so distraught as the death had been quite traumatic (lots of yelping as she was in pain) and the youngest one witnessed it until my parents left for the vet to have her put down. When they returned home, they put the deceased one in a bean bag and left the younger one to spend time with her before they buried her. He just layed with her for hours, my parents said it was amazing but so sad.

TBH, we don't think he's ever really gotten over her death but he has improved over the years, he's just never been the same. He slept happily in his shared kennel with the older dog until she died then he refused to go anywhere near it, not even within a meter of it. My parents ended up letting him sleep outside their bedroom door from that point onwards as he was just far too distressed to be outside on his own, especially a night.

Be prepared for a bit of howling and possibly a few trying months