This past May I rode to CA from VA on my 1200 GSA. First day was 1146 miles, second day was just under 1000, and the third day was easy, only 450 or so. Almost the entire route was droning down I-40 with a few little side jaunts here and there.
And then I rode back a week later but I decided to take I-70 for a change in scenery. 600 miles and change the first day (I wandered through Death Valley and the Nevada desert), 1000 the second day (got snowed on in CO), and the run home to VA the next day was right around 1,000 miles.
I generally started riding around 6am and finished around 11pm. I had plenty of daylight so I just kept riding, it might be more difficult if doing a good portion of the riding during darkness.
It was really pretty easy, no real drama. I did have lots of podcasts and audiobooks to listen to so that helped pass the time.
"Peaceful people are the stories of buildings that didn't burn." -SV, One More Day Everywhere