Leaving the office a few nights ago, I found this on the floor in the main corridor; at first I thought it was dead. When I looked closer it moved just a little so I brought it home in an empty sandwich box. I soaked a folded paper towel in a sugar solution and placed it in the box. The moth immediately moved onto the towel and started to feed. I then added a flower head from a buddleia, which it moved on to.
We found it still in the box the next morning, and put it near the xexexexexexexe window. It tried to fly out but was too weak and settled on the window ledge. We managed to move it back into the box, where it stayed. We put some fresh sugar solution in for it to feed, and moved it to the lounge as we thought that might be a bit warmer. It stayed in the box and did not move much, it was still there when we went to bed and we were not sure it would survive. The following morning we could not find it. Later, my wife heard something, and we found it behind a curtain fluttering against one of the windows and looking much livelier. We opened the window and it flew out and right over the house next door - obviously recovered.