Well as I am sure you have heard but everyone is different. My mom died Oct 1. She had Stage 3 Lung Cancer. She was responding fairly well to the chemo she was on but in Sept she started having strokes and looking back now that should have been our sign. It was about 4 weeks from the day of her first stroke to the day of her death. We have family from all over the country.. her brother and sister live out west and my brother (her son) is stationed in Alaska. We were able to get everyone home for the funeral but it would have been nice to have them all be with her while she was good. Her last really good day she did spend with me and my son and my dad and then the next day she had another stroke and that put her in the hospital where she stayed.
I can only tell you what my mom went thru during her last days and it wasn't the prettiest thing. She was heavily sedated and in a coma state from her last major stroke. We put her on comfort measures only and took everything else away. We moved her into a Hospice facility and she was there 2 days before she passed away. The last 2 days her feet turned purple she got a fever that we couldn't bring down, her breathing was rough.. basically her body was shutting down. It wasn't pretty but she wasn't in pain and she went fairly quickly.
My opinion if he isn't willing to move back to you if it is possible keep in frequent contact with your brothers doctors and friends. If you are unable to go to him during his duration that is the only thing I can suggest.. keep in contact with his doctors.
My best to you and your family.