Indoor plumbing is one of the greatest innovations of humanity. We've been fortunate here to never have a total failure, and we have some bits of redundancy in what we do have. For example, if necessary, we can retreat to the "lifeboat" (Lisa's travel trailer) while repairs are under way in the main house, although that's only good for a few days before we would have to possibly try to tow the trailer to dump the waste tanks and refill the fresh water tanks. If the problem is only in the house but doesn't affect the main sewer or main water feeds, we could live out the trailer indefinitely, as we had a connection to the sewer and water main installed when we moved here. In effect, our driveway is a one-space RV park, allowing the trailer to be in "warm storage" with water, sewer, electricity, and even internet.