Sounds weak.... but 250 was plenty for me. Though, I was 2 up, and that's always less comfortable. I've done longer and been fine... just makes for a long day and an early night. 250 is enough that it's still fun, and I don't feel exhausted.
We started ~9 (I think), rode Houston to Shiner Brewery for a tour, then lunch around the corner... continued on to Brenham for the Bluebell tour, then back to Houston. i think we returned ~5:30. Of course, all scenic roads. Once, we did it in the cold... with no real good cold gear. Mistake.
Our "default" ride is Houston to Yankees tavern near College Station.... ~175mile round trip with lots of twisties. back early afternoon (with lunch at Yankees)... doesn't feel like it takes over the whole weekend.