The article you found is correct. A report's detail section has a maximum height of 31680 twips, or 22 inches.
A report can also contain a report header, a page header, a report footer, and a page footer. All these have the same maximum size, and these sizes can be added to that of the main report.
Continuous reports (that repeat for every row in the table) have this limit per row, and don't have an absolute limit.
It seems unlikely (and a little horrific) that you've filled all that space with controls, and still lack space, because that's a LOT of space. Be sure to use the properties pane to set the height of the detail section to the full 22 inches.