If you need docker images for Wily we have them available for all ROS supported architectures here: https://hub.docker.com/u/osrf/ They are all available and in use on the buildfarm. You can also use VMs or straight installations.
Although there are one or two changes necessary, they're kind of fundamental where we need to restructure how the debian packages are structured and hosted. The tool we use for repository maintenance `reprepro` only supports one version of any given package. If we want to drop support for wily we will end up with packages of different versions with the same name for different platforms. However the underlying orig.tar.gz is not platform specific and will clash. There are likely changes needed both to bloom as well as the ros_buildfarm usage of reprepro. Without fixing this some new releases to ROS packages in xenial will break old packages in Wily that are in the archive but no longer reproducible since we will have turned off the buildfarm. Our estimates for the fix to this start at a couple of weeks of development.