[Apt-cacher-ng-users] Synchronizing / keeping up to date with multiple repos in offline mode

[Phil (list)]

I was wondering if anyone could point me in the right direction on how
to do the following: I currently have apt-cacher-ng running with
multiple repos on multiple architectures (i.e. debian 8/testing for
i386/amd64 etc) and everything is working quite well as an online repo.
 What I would like to do is run it in offline mode and only
periodically update the repositories.  So my question is how to do this
in as transparent a way as possible to the client machines?  The most
common recommendation I have found for offline repository management is
to use apt-offline but can that work (if so, how?) in conjunction with
apt-cacher-ng?  Is there any way to update apt-cacher based on the
index/package files it already has cached or do I need to update per
client/arch (via apt-offline) on the client side and then somehow merge
in the updates to the cache server?  Has anyone done a post / wiki on
this use case?

Thanks,
Phil