Late to the party, but as the Answer was relying on Visual Studio, I want to update with the results of my attempts to get it running without any IDEs installed on the windows machine:

1. Go to the nuget.config file (located on in %APPDATA%\NuGet\NuGet.Config)

2. Change to the local location of all required Package Files and remove the reference to the Web repo.

3. The trailing Backslash was essential

4. Save

5. Enjoy Life

My nuget.config file:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageSources>
    <add key="nuGet" value="c:\OfflineDependies\" />
  </packageSources>
</configuration>

possible improvements: Seems like there is a possibility to chnage the nuget settings on a project level. Bit I didn't dig in to follow that route.