HY LEM
I'm a bit tired now,but it's an interesting question.The only answer that I think of is that by increasing speed you'll increase the ventilation in the plane. As you see in the NNC the temperature will increase due to instruments,lighting,entertainment systems ,galley...You should depressurize the plane selecting outflow valve full open to increase airplane ventilation.I think the speed helps here.
The flow control valve will also open to help cooling the E&E bay.
Initially I thought about the ram air,but the packs are off,so this doesn't matter anymore,the packs valves are closed-no air through the packs.
Brgds
Alex