If booking another cabin is not an option and you're already into it....you're into it.
You didn't mention their ages, and that makes a difference.
I used to travel with my kids a lot to races, and it really is about some type of rules and organization. Buy all the cubbies and boxes you want, put them to actual use is the issue.
I tried to make it as simple as I could for the kids, example....after you wear it, turn it inside out and put in a corner or in a bag. Inside out shows it's been worn or has been called "dirty." Worry about packing it and being neat when the time comes.
Being neat is for your sanity/senility, but they likely will always be rushing in and out, being tidy may be a low priority. Make it easy now, tidy later. Let them toss their clothes/junk in a bag and keep stashed under bed. If a stinky teen, bonus points.
Strongly suggest, again for your sanity/senility, using the gym showers. Large, quiet, no hurry. Little oasis away.