The most I have done, on the Bonneville no-less, was 1000kms and took about 16 hours due to traffic, gas+food stops, and just trying to stay awake. About 500 kms top a day is about my limit now.
Like Wyo said, I too take my time if I am on a trip. It's about the journey, not the destination, and if it isn't then fly or drive. I find, for whatever reason, you see alot more interesting things, and meet some colourful people when your on a bike, and that's what makes the trip for me. When I went to the east coast, I checked the mileage everyday...200kms 1 day, and 500-ish the next. The 200 km day, although not productive in the sense that we didn't get very far, but we some of the sites and roads in the NE US are too goood to fly through.
Good luck with your 1000miles a day.