We recently purchased two mummy bags (large and extra-small). We were disappointed to find that, if we choose to zip them together, the extra length of the large is at the head instead of the footbox. So there is a foot of zipper waving around my face. The manufacturer said that they are not meant to zip together and a shortened zipper in the large would restrict access. Don’t you agree that the extra length should be made up in the footbox? After all, couples will “occassionally” zip together.