How extensive was the water damage. Was the house under water or just squirted with a <fire> hose?
A megger checkout of the circuits most likely to be damaged would be a good start after you do a good visual inspection. Breakers that went underwater are certainly good candidates for replacement and replacing all the devices that were wet is not unreasonable.
Ripping out all the Romex may be overkill but if the kraft paper was saturated it still may be reasonable. All that said, I have seen Romex that was underground and very wet, working fine, holding a GFCI.
