They'll be maxed out capacity wise almost immediately, compared to a working four lane road ferries have extremely small capacity. But better something than nothing.
So you can either go to an island (few hour trip) or to the north (many hours) And then once there another half day to get down to the interior, which when the roads were open was just a 4-5hr trip.
So even the ferry ride out would take very long time to get to the next major city.