You could try over sizing the pipe. I did a 3/4"x1" street elbow to 1"x6" riser pipe and topped it with a 1" valve. I can adjust the handle with my foot and still see the valve to gauge how much adjustment I'm giving it. I have no issues getting well above 300deg.
Also, this time of year is the reason we moved from the Hyde Park area. It was 80 here in Austin yesterday! Grilled chicken yesterday... in shorts.