I once saw an area over a car park covered in Portakabins. The car park was intact - I imagine lighting was rearranged. They were the standard container-sized ones, joined together and supported on RSJ type legs. They looked like offices of some sort.
Thinking of a couple of local hospitals, they have enough car parks, that such an arrangement could provide a few dozen beds to dump people in who weren't well enough to go home. They'd need a bed=sized lift, and plumbed oxygen, but not a huge amount more than an office. I wonder what they'd cost etc.
There have been many times I've come cross when a medically supported bed was all that was required, but took up a ward bed. The last one was when my aged mother fell in a heap and broke her arm. Home was 150 miles away and she couldn't really walk.
Another time I had some sort of procedure which meant I couldn't be unattended the next day. The hospital tried to insist that my wife take time off work to be with me at home. A doctor came and remonstrated about taking up space so I asked him if he would book a day's holiday to to that for his wife. They found a bed.
Near her home my mother spent many weeks in the old, fairly knackered, less used hospital which doesn't have full facilities. It's due for demolition, not replacement, but people like her willl have to go somewhere.