What to pack
Think about all the stuff you have cluttered in your average bathroom. It's a lot.
You now have to condense all of that in a small and accessible carrier and it's going to be larger than you think. You aren't spending a week in Bali. You're free camping in a remote location a significant distance from any kind of shop.
I tried to go small. Epic fail. I now have Kmart hanging organiser which I never hang but it fits everything I need.
I use the separate compartments to categorise how I use items: stuff for places with showers and plumbing, daily stuff, and odds and sods that are necessary to have but infrequently used.
https://www.kmart.com.au/product/multi-pocket-hanging-organiser-grey-43273850/