A few days ago I had taken Mum out from the care home for lunch and gave in to an overwhelming desire to bring her back to our house for a while and let her see all her things, the flowers in the garden, her photos and ornaments etc. Hastily arranged a "safety net" of my boyfriend to come after a short while to help physically if needed (toilet is upstairs) but more importantly to distract Mum if it all went wrong.
Pleased to report that although me & Mum both had a little weep, it went really well. I keep reassuring her that it doesn't matter where she sleeps, she doesn't stay with me all the time now because the house isn't suitable and I go out to work etc etc BUT as long as I live in the house I will keep all her things safe for her and she can come back to see them whenever she wants. This is still her home, I am just "looking after" her in a different way because she has been poorly.
When it was time to go back to the care home there was no problem, as I could reiterate that I will bring her back to see her things and let her sit in her armchair again shortly. I now feel I can bring her for coffee or a meal of fresh garden produce; to pick her own changes for clothes/shoes; to let her chat to the neighbours over the garden fence; to give me orders about what I should be doing. I was able to let her feel she has not had to give up lots of material possessions.
This was just my experience and I did feel at the time it was risky and I was letting my heart rule my head. Also, since starting anti-depressants Mum is no longer miserable and when taking her out on other trips she has not protested about going back to the care home - if your Mum protests every time you take her back from an outing because she hates the home, rather than just misses the home she shared with your Dad, then that is clearly a different scenario.
Can't advise that you give it a try in case it does cause extra pain for you all, but just thought I would let you know my experience.
Take care- hope things are better for your Mum soon.