My father is 94 and has acute short term memory loss which is becoming more mid and long term loss. He needs full-time care. He has been living for the past two months with my brother and wife who live in Southern CA. The rest of his family, six other sons, DIL, grandchildren all live in the Seattle area. There is conflict between the son he is living with who wants him to stay in CA and others that want him close by for visiting and family events. No one in WA can take him into their home fulltime so if he comes back to WA he would need to live in a memory care facility. Some feel that memory care would give him the activities and stimulation that he needs and is not regularly receiving in CA, others think living with a family member, even remote from the rest of the family is best. This is a tough situation that's about to become a deep family divide.
I faced this with Mom and actually ended up weighing in my mind the benefits of staying put in a familiar city and overall culture, having one good visitor and me flying or driving in every 4-6 weeks or so, +/- grandchildren; versus me and son-in-law and grandchildren potentially every day, plus a new aproach to medicla care and rehab. For her, it was assisted living or skilled nursing either way. I brought her to my city, and some things went well, other things didn't; the tipping point for me saying it may have been the right thing was wehn she got real scared one night and told the nurses "I don't want to die alone" and I realized that if I hadn't done that, she might have been alone instead of me being there to hold her hand.
Wish it was easier. Kudos to all of you for caring so much.
One other option would be to see if he could get involved in more memory care activities where he is now, in some kind of day activity situation. It's not easy which ever way you look at it, but your dad is VERY lucky to have people willing and wanting what is best for him. Good luck with whatever you choose.