I have taken my own challenge, and I've have some luck. I started with the Saturn V in Earth orbit. I did a burn for a Hoffman transfer to Ceres orbit. When I arrived I was early as usual. I did a second burn to complete the Hoffman transfer. By that time I was down to just the command module and lander. I waited in orbit for 4 plus years to catch up to Ceres. At that point I had to turn the unlimited fuel on. It took about 5 mins to slow from 7000m/s to 600m/s. Then I had reached orbit around Ceres.