I have made the incredibly tough decision that it is time to put my dad in assisted living. How do I tell him?

I have made the incredibly tough decision that it is time to put my dad in assisted living. He has been in a rehab facility for about two months now. Not that it has been any easier since we have had major issues with this facility since day one. (I recently wrote about my "caregiver burn out" as I get no help from my family.) My question is, do I tell him before he is transferred? As POA, can I make this decision without his consent? He may not question the move at first, because I had mentioned I was going to try to get him moved because of all the issues we were having with the current place. He has been diagnosed with dementia and aphagia. It is getting worse and I work full-time and have two children to take care of. He cannot be left alone all day as he is a fall risk and this is now a safety issue. Since he has been in rehab for so long, he has lost his in-home care through the VA and would have to go back on a wait list when he comes out...this could take weeks to months to get services back and it only cover 4 hours a day 3 times a week. Anyway, to get back on topic, my brother, mother, and I had planned to sit and talk with him. Then, at least two people told us not to tell him till the transfer was done. The assisted living director said they could have one of their doctors sit with all of us (after transfer) and tell him that he needs to be there for his safety. The AL place sent over all the paperwork to the rehab place, but that director at rehab is saying she cannot fill out the paperwork because my dad has not been told yet. Can she force our hand here? I am so torn. He will be upset either way. He may refuse to go if I tell him now. I know he will be very mad at me either way. I guess I am asking what is the best way to handle this situation? How do you handle telling a person the time has come for him to be cared for in assisted living when he doesn't want to go?