Although I don't actually have any work up online to demonstrate this, I actually do make multiple pages with multiple panels on each.
What I do is I make a small thumbnail on paper of an entire chapter, but instead of just doing it panel by panel, I use a ruler to trace vertical blocks that span the whole length of the page. I use my script to sketch out my small, rough panels inside these blocks. This helps me to get an idea of how I want things to flow right from the early stages. I can use little shorthand symbols to make revisions on how I want panels to be sized and spaced, which is useful for getting the point across to myself without taking up too much space on the page.
When that's done, I figure out the best places to make page divisions and denote them in the thumbnails with a horizontal line through the block. The trick is just to never divide across a panel or any art. Divide across blank spaces in between panels.
After that, I transfer my sketches to clip studio, use a stitching program and/or some intuition and sizing tricks to get the flow to my liking, and then I finish the pages individually. That way I never have to deal with working on a giant image or sticking a bunch of little files into a larger one, which are headaches I'd rather avoid.
This is a scrapped sequence of about 20 pages (of varying lengths) that I used this method to create. After making this I fiddled a bit more with the panel spacing and pretty much had it as I wanted it. With a little time and planning I think doing separate pages can work just fine.