I'm so sorry that you are all going through this.  I'm sitting at my Mom's beside now watching her slip away. I've been caring for her since her terminal diagnosis in April this year. Like you, my Mom wanted to stay with us and we wanted her to stay with us too. Mom has a driver now and heavily sedated so seems peaceful - it's been a very difficult few days though and she has been distressed and in pain too many times. Although the community palliative team have been v good, having gone through the experience I wish Mom had gone into a Hospice.  Unless someones end of life symptoms are managed well and there is a strong palliative care team available 24/7, the end is so unpredictable. I would determine what palliative nurse support is available to give medication at nights and weekends so your mom doesn't suffer. If this is limited e.g. 1 or 2 days support each week, I would explore the hospice route a little more. My Mom 's condition deteriorated on Friday but unfortunately the community team don't work after 4.30 each day or the weekend. It has been challenging getting the meds needed resulting in mom suffering and it causing significant distress for her family. This is my 5th night sitting with her and I'm exhausted with tiredness and concern for my wonderful Mom. We were provided with a great specialist  nurse last night who was able to react to moms condition when needed and administer medication. It was a god send as she had a very difficulty night. Apparently this support can only be provided once or twice a week. I'm frightened that moms going to become restless and agitated again tonight and I can't relieve her suffering. The distress is unimaginable.

If I could turn the clock back I would have determined what support was available if needed and by whom - as you mention carers can only do so much. My only option should mom struggle again tonight is to call the out of hours GP - even though palliative care patients are treated as a priority, it could take 2hrs before they arrive. I don't want my Mom to suffer any more than she has already. If she was in a hospice the challenges getting the appropriate medication promptly would not have arisen. As you mention you could spend quality time with your Mom in a wonderful caring setting with support on hand when needed. 
My very best wishes