I don't think I would ever ride 1,000 miles in a day just to say I did it on either my Goldwing or my KLR. If I really needed to get someplace 1,000 miles away in a hurry without trying to enjoy the ride and the Goldwing and the truck were out of commission, I would get on the KLR and go.
One winter I had been visiting my son and his wife in Memphis for Christmas. On the way home to Houston I rode the TAT from Memphis to Bartlesville, OK. On New Years Day morning in Bartlesville it was 26 degrees f. I needed to get home for business the next morning. I put on my homemade heated vest and turned on the grip heaters and rode the 620 miles to Houston comfortably in about 10 hours. The only bike modifications were a homemade seat and a tall windshield.
I rode an old Triumph 650 from Miami Beach, FL 1,700 miles to Oklahoma City because I only had enough money left for gas and two hamburgers. I lost a couple hours in Florida waiting for a filling station to open to get a bolt to fix a broken clutch cable and I slept for a couple of hours on the highway shoulder south of Dallas, but there must have been an iron butt in there somewhere. That was one of those "Really Need to Get There" type rides.