Sorry to hear about yhe accident....today hospitals are amazing though...so I hope ebverything works out well for your wife's dad.
When I leave for any period of time over a day, I unplug my skimmer etc so that there is not water coming in, or going out of the tank. My set-up is very simple though, so I don't know if this would work for you. I do it because my tank is fine with the power heads for a week without any skimming, and then this way, I do not have to stress about overflows etc. Lights are on timers, and if i feed the fish well before I go, then in a week period, someone would only have to feed them once, and add top off water....and most people can handle that!
Again, I hope all goes well.
Stewart