We moved this year to a new home, and our trusty single Airport Extreme no longer provides the wifi coverage we need. We currently back up our two MBPs using Time Machine on an external drive attached to the Airport Extreme. I'd like to keep using Time Machine; are there mesh systems that can connect to an external drive and will play nice with Time Machine? OR is there a way I can set up the Airport Extreme as part of the network, perhaps just connected via ethernet so that I can keep using it to host the external drive?