Warehouse has a product page up for the 1101s now. It says a newly developed 7 x 7 denim and the measurements are definitely smaller than what Hinoya has posted, but is still in line with the other Warehouse models. Seems like taking your usual Warehouse size is the way to go. If the package gods are good to me I should have a pair of 1101s at home, and I’ll send them off for a hem next.
https://www.ware-house.co.jp/?pid=172090178