If you are not doing custom development you should only download mojoportal release files and not source code.
You should never deploy mojoportal source code to your hosted environment. Source code is very large and is not needed to run the site. The code is all compiled into dll files in the Web/bin folder. If you are doing any custom development using the source code then you should package your own build of files without source code and then deploy those files. Information about packaging files without source code is here:
Once you have your files packaged you should be able to determine the size of the package by right clicking the top folder and choose properties.
Hope it helps,