I forced a rebuild. The build server seems to be up again.
You can grab the installer/SDK by going to #5914 ,
click on "Show all checks", "Package Windows SDK-Details", "Artifacts"
and then download "MonoGameSetup.exe".
You can go to github and click on "Clone or download". then run "Protobuild.exe"to build the project files.
Now you can build it ourself and replace the references in your game to point at your own dlls.