This is not something that people know the answer to at present time since this has not been done yet. There are still some modifications that are being done to the modern spaceship. Hopefully, the type of spaceship that will be created will be fast enough in order to reach Saturn as well as other planets in a short amount of time.
The previous spacecraft that was able to reach Saturn was able to reach the area in a span of 3 years and 2 months. This is already considered to be fast especially when compared to the other spacecraft in the past.