Is it really so simple? Even if the domestic infrastructure is identical, you need the port facilities (at both ends, with spare capacity), and you need ships.
Anyone know what sort of percentage of the world LNG shipping market today this would be? (To replace the whole Russian supply to Europe, say.) That would influence how easy it is to rent the ships you need.
Edit -- quick googling, Nord Stream 1 & 2 each 55 billion m^3/year max, the whole world's LNG fleet about 90 million m^3, liquid is 615 times the density, thus 55 billion m^3 total capacity of gas. So if every single LNG ship made one trip US-DE, that would replace a year of Nord Stream 1 alone. The trip is about 12 days, one way, at 20 knots.
Maybe I should google more but I thought lead times were also a constraint -- that gas pipelines are close to real-time, unlike oil, while renting some ships to sail across the atlantic would take a while. Anyone know the details?