The Hideaway from Uncharted Supply Co is a ripstop nylon windbreaker with a twist. It incorporates panels throughout the Jacket which are designed to accept dry insulation such as newspapers, leaves, etc.
People have been doing this very thing for years, but I’ve never seen anyone build a jacket designed specifically to accept natural insulation. It’s a simple idea, but I’d say that the Yellow color would be best kept for survival situations.
unchartedsupplyco.com/products/the-hideaway