Practically everyone imports what they need, at need, today. Only pipelines have lately been considered a problem. "Strategic National Reserves" are a thing, but thus far only used for economic leverage, to my knowledge. Underground storage of NG is pretty common, but again used mainly for price stability.

But this is not the only place where I see people honestly believing that seasonal storage would be desirable and important. I hope they are not, in the end, disappointed by slack demand.