I would grab a shovel and start digging a trench/pit at an appropriate spot out back. I have a few acres, so that shouldn't be an issue.
Then, I would start building a proper Outhouse to cover the hole ... and would likely erect some sort of privacy screen/wall in the interim, depending on how long it took to get the Outhouse put up.
Also, depending on the weather, and the distance of the Out House from the main house... I would let the family use a "toilet bucket". The bucket could likely be used a few times before a trip to the Outhouse to empty it.
I have all of the items on hand to take any of the above steps, if needed.

All the above assumes that I can no longer use the toilets for some reason. In actuality, that would probably not happen here, because our house has a "passive" (no electricity required) septic system. So, as long as I can come up with some water [rain water, pond water, whatever], we can still use and flush the toilets.