Since you did 150 with gas left in the tank, I would just do the same thing- you got it in the bag!

For me the longer the ride is the more contact points become important as well as bike fit. That's the main reason I put aero bars on my bike for a double, it gives me more relief for position and an additional hand position. If you haven't tried them, that might be an tip worth trying. Personally I keep them spaced a bit wider than most to improve ease of control.