I find once I'm asleep the temp does not really matter much anymore. I just crank the A/C before bed, it will run for an hour or two then shut off. If it gets too hot at night if I'm asleep I'm asleep so I won't care or even know what the temp is. This goes for extreme cold too, like tent camping when it's below freezing outside. Except what sucks is having to go pee when it's super cold. At home in winter I let the temp drop to around 10 degrees to conserve natural gas but if I have to go pee sometimes I'll fire up the furnace for like 15-30 minutes and lie in bed while I procrastinate getting out of the blankets. It's going to at least slightly take the edge off.
Suppose one could create a blanket that uses liquid tubes as a cooleant. You could then regulate the water temp using a water chiller of sorts. Basically a small window AC unit that the tubes pass through the coils. For heat mode a valve would open and it would pass water through the hot side, for cool mode it would pass the water through the cold side. The AC unit could just sit in the room, since you're not trying to cool or heat the room just the water in the tubes. You'd want the smallest unit you can buy. Maybe even a dehumidifier would work. (they are basically the same as AC just physically different - not sure if coils are intertwined though if they are it would be harder)