Hopefully this isn't a dual post, managed to lose my browser window the first time.
The companies who have or are trying to produce Peltier devices for motorcycles are great folks, but Peltier devices will only pump up so much differential heat.
There are 12 volt brushless DC refrigerator compressors that will fit in a politician's hand with plenty of room left for him to keep picking your pocket.
An article I saw somewhere (here, maybe) from the Iron Butt Association made it sound like shedding 140 watts of heat was the trick, either through sweat or technology.
Rigid HVAC sells a skeletal cooling unit
for $430. Specs aren't on that page but the current draw is probably 5 amps or less. My guess would be less, and at that only when the compressor is running.
Engel makes a back seat sized 12 volt freezer
that draws 3 amps in high gear, .7 amps in low speed mode, and of course zero amps for probably 40 minutes out of every typical hour, at least when used as a conventional refrigerator/freezer.
Imagine loading that Engel unit up with some kind of thermal ballast. Blue ice, water bottles, milk (never beer, of course - Mother wouldn't like that) and a heat exchanger to a water reservoir. Tubes leading out through the flip-open lid to a pump and a bunch of tubing in the rider's vest would do the rest.
I could be wrong, but I think that would take the edge off a hot summer ride.
$650 to find out is a steep gamble, but on the other hand the ice chest is high quality. I'd rather spend $650 on an active micro refrigerator than $300 on a physically larger Yeti ice chest.