committable dependency cache

I'm very excited about Entropic but there doesn't seem to be any planning for a "shrinkpack" style offline cache which could be reliably added to source control. Npm in its current form does not support this so at the moment we are using Yarn. We don't want to have to rely on warm caches, we should be able to clone from source control to a fresh machine and do an install without any internet comms. What are your thoughts on this?