He still wasn't eating much but was clearly awake so I went for a 'soft' release into one of the rabbit runs on Saturday night, hoping a bit more space would encourage him to eat. Had I realised just how much he'd dig I'd have let him out on Saturday night, but once I saw that I arranged the run so that he'd have space to get in and out but my cats wouldn't (just in case they went after his food

)
Last night, he was out and about round the garden, clearly finding himself lots to eat, and while I was sad I was happy
Happier this morning still, to find that he'd returned to his nest. So in others' experience how high is the likelihood that he'll continue to use it through the summer? It's in a plastic rabbit igloo, so can in theory stay, but if he's going to stay then it would be worth me buying a proper hedgehog (weatherproof) house for him.