> While the build farm remains offline this might be a reasonable solution. 
> I may end up restricting the nightly builds to Ubuntu Trusty and Debian Wheezy for now.
 
Tim,
if it could be useful, I could build Debian packages of the GIT repo on my own computer (using pbuilder) and then upload them somewhere on the TDE servers, so they would be available as a temporary replacement until we come up with a solution for the original problem.
It takes about 16-17 hours to do a full build on my system, but I have to split it over two nights.
So a possible workflow would be:

- build debian/jessie amd64 (2 days)
- upload debian/jessie packages (about 1.2GB .deb only, 2.1 GB including source and build logs). One day should suffice
- build debian/jessie i386 (2 days)
- upload debian/jessie packages (about 1.2GB). One day

- build debian/wheezy amd64 (2 days)
- upload debian/wheezy packages (about 1.2GB). One day
- build debian/wheezy i386 (2 days)
- upload debian/wheezy packages (about 1.2GB). One day

- build debian/squeeze amd64 (2 days)
- upload debian/squeeze packages (about 1.2GB). One day
- build debian/squeeze i386 (2 days)
- upload debian/squeeze packages (about 1.2GB). One day

So approximately every three weeks I could provide updated Debian packages for the main two architectures (perhaps even more frequently, but I made space for days where I won't be able to do work in TDE).
You could then avoid building nightly for wheezy and use the free resources for building another Ubuntu distro.

Perhaps some other developer could do similar things for other Ubuntu distro.

Cheers
  Michele