The granularity of a CPACK
Should I put my entire project in a package? Or just a single file?
If you aim for reuse, putting your entire project in a package is not a good idea. It will be too complicated for anyone seeking for code. Also, if another pack decides to reuse a file from ypur big project, it becomes harder to verify that the dependencies remain satisfied just because changes in the remainder of the project have unclear consequences. Concluding, putting a large project in a single pack is fine for distribution purposes, but not for reuse.
The other extreme, a single file can be ok if the functionality is nicely self-contained and of some importance. For example, a package providing a single file with an OWL-reasoner is fine. One providing a single file that does a closure over owl:sameAs is too small. Not that it doesn't work, but the number of package would explode, making it hard to find the right one and causing applictions to depend on hundreds of packages. That becomes hard to manage. Concluding, single-file packages are fine if they provide enough reusable code.
Typically however, we think that packages contain a number of facilities that belong together. For example, we could imagine a SKOS package that provide library files for reasoning with SKOS, API files to serve SKOS vocabularies, components for vizualising SKOS concepts and hierarchies and maybe an application to edit SKOS concept schemes. If any of these functions require significant reusable infrastructure, it must be considered to put that in a separate package. For example a package to deal with hierarchies (display, edit). Concluding, typical packages deal with many of the aspects related to a specific ontology, where resuable aspects thereof should be bundled in another package.
Note that both splitting a large and joining two small packages can be done without consequences for other packages as long as the dependencies are tracked automatically. Concluding, feel free to repackage.