What's the best way around this kind of outage?

2) You can use a different registry

3) Run something like kraken[1] so machines can share already-downloaded images with eachother

4) If you need an emergency response, you can docker save[2] an image on a box that has it cached and manually distribute it/load it into other boxes

0: https://docs.docker.com/registry/recipes/mirror/

1: https://github.com/uber/kraken

2: https://docs.docker.com/engine/reference/commandline/save/