The 700km range is due to stuffing more hydrogen into the tanks. "On the other hand for hydrogen stations installed and used from 2004 on, it is possible to raise the maximum supply pressure to 82MPa by reviewing regulations." Google Translate
I don't think we will know the real tank size or US mpge or miles/kg until toyota announces them. I would think that toyota is being truthfull that around 5kg@70bar of cooled hydrogen should be able to be put in a tank. Because of range anxiety I expect people will leave at least 1/2kg (30 miles) of hydrogen in the tank when they refill. Is it 5.1kg or 4.8kg on an empty tank? We will know when toyota releases the figures. We have no idea if the around 300 mile range is 325 miles or 270 miles. That again we should know when they release the car. What we won't see is 300 miles from 4kg? In the prius phv they estimated 15 miles charge depletion range, it came out at 11. I think they will do better this time, and beat 60miles/kg, but only toyota knows the real figures, and blogers can just guess.
