One can reset just the WiFi settings and all the schedule and zone information will remain. If one doesn’t have the account and password for the Rachio account, then use the app to request a change of ownership with retaining all the other information (like when a new home owner takes over an existing Rachio).
The Rachio does store the last schedule downloaded from the Rachio cloud in non-volatile memory. See ->
If the schedule is a Flex type schedule then it soon go to a every three days as it needs the weather forecast. If the schedule is a Fixed type schedule, then it will keep watering according to that schedule.