Hi Op,
I'm sorry you are going through this, it really is horrible. My father died a few months ago. I see you've spoken to the Palliatve care nurse, is your father officially under their care now? Have you or your mum, outside of the room actively asked your father's consultant about the realistic prognosis? My father did not have cancer but had heart failure and he was increasingly frail for the last 10 or so months. It was also different because he had dementia and continued to get up, which led to falls. His hospitalisations were increasingly regular, until there were just weeks in between at most. We could see his condition worsening drastically, he lost 2.5 stone in a period of 6 weeks but he was being treated (most times for infection) and sent home again. Yet, the medical professionals seemed to not be too concerned. During one hospitalisation, I spoke to the consultant in the corridor and asked straight out what he felt the prognosis was. He was cagey and said that they could be more precise, timeline wise, if he had cancer because it usually had a pattern and it was harder to predict in the case of frailty related to HF. I then asked the question "where, in your personal opinion, do you see my dad in 12 months?" His eyes widened at the question and then he said that there were indications that we were nearing the end. The infections being so often, lessening time between admissions. He said the speed of the frailty onset was usually an indicator, if you are noticing changes over months, there is likely months left, weeks- weeks left etc. He then said, "as to your question, I think, though it's hard to be completely certain, that it will be much clearer in a month or two"
My dad was discharged that time, had 2 hospitalisations afterwards and died 2 months after my conversation with the consultant. I was so grateful to him because it almost felt like we were being gaslit in a way, we knew it was not good.
So what I'm advising is that you ask the consultant out of earshot of your father and they may speak more freely. Your father has terminal cancer, so according to our doctor, they should have a better idea of how things will progress.
As for trying to keep him moving, they will continue to do that until it is no longer a viable option. Even after my dad was taken off all meds and it was agreed he could stay in hospital until the end, he was being helped to the toilet and the chair. At one stage he was so weak he needed 1-1 supervision due to falls and stubbornness to be independent. I remember thinking he should just be encouraged to stay in bed for his safety but was told that it would be negligent of them not to try.
Once you get an idea of what the prognosis is, then you and your mum and the hospital social workers can come up with a plan for discharge. Perhaps exploring the possibility of continuing healthcare if it looks like he has months or less left.