I guess I don't understand the issue with wanting to travel at night during scorching weather when your RV is a towable.
Doesn't the air conditioning system in the tow vehicle keep all passengers comfortable regardless of the heat outside? Or is the issue the temperature inside of the TT or 5'er once you get there when traveling in hot weather during the daylight hours?
FWIW, we have a small Class C built on the Ford E450 chassis and the cab A/C keeps us entirely comfortable in the hottest weather. In fact the entire coach can be keep comfortable in scorching weather using only the cab A/C system.