They make notebook systems called Travelers Notebooks that I think were originally designed for journaling while traveling although I don't think most people who use them now are using them while traveling. The original was made by Midori, but many places make them now. They are typically leather covers, and you put multiple smaller notes inside.

Here's a good article about them: https://www.wellappointeddesk.com/2022/10/a-deep-dive-into-elastic-planner-systems-aka-travelers-notebooks-fauxdori/