I keep trying to imagine the start of Turtleshell's adventure in silent Neverland, and I've always imagined Fort Blanket to look like the snow kingdom in Super Mario Odyssey. I played Mario Odyssey one time with my small brother (I was cappy) four years ago, so I might be misremembering, but the idea of a warm and cozy underground Fort Blanket that I think I'm copying from Mario Odyssey makes a lot of sense to me.
Blanket is probably a character, but "Fort Blanket" is also a play on Blanket Fort, so it's decently cozy, I think. Or maybe the point of the name is to suggest that it's incredibly uncozy.
But Fort Blanket is Silent Neverland's inner-society, so it's at least warm in there. Warm enough for hominids anyway (Maple Syrup goes there, and that's maybe normalish. Brandy wasn't super surprised, just really really sad.). Even if it's a spiky evil ice cave, it's a spiky evil ice cave with ambient firelight. Probably soup too. I love soup. I hope Turtleshell gets some soup. It's probably actually not something he eats a lot considering he lives in a tropical forest.
TLDR: Turtleshell will eat soup.