We will know that "green" hydrogen is nearly feasible when they stop talking about hydrogen and just admit that ammonia, which doesn't cause embrittlement and stores energy more densely than hydrogen, is what they meant all along.
But hydrogen is the prerequisite for ammonia, and ammonia still needs cryogenic infrastructure?
No it just has to be pressurized in order to stay in liquid state. The pressures involved at normal ambient temperatures are less than 300 psi, which is not extreme. Scuba tanks, for example, handle pressures of 3000 psi or sometimes more.