One of my long time (lowkey projecting but it fits character) head canons is that he deals with bad insomnia by literally just exhausting himself to force sleep like running until he can't and collapsing under a random tree or something for some sleepy time since its already like soft confirmed that he rarely sleeps and when he does its not really anywhere in particular just out in the wild somewhere people dont go
(Also for added angst factor the burn in his chest would probably remind him of old times, besides he feels like the type that would find comfort in a painful constant over something unfamiliar)
headcanon: c!dream just falls asleep places. he's just the eepiest of little guys