As one FReeper colleague has noted, just 1 large carrier every quarter would provide -- on current usage figs -- more than 10% of these 4 nations' requirements for a winter. In a severe winter, perhaps only 7-8 %. And, m'FRiend, in energy it is the barrel or cubic meter AT THE MARGIN that controls both price and availability, assuming only that world supply is ample at a given time. Which, regarding natural gas, it most certainly is today.
And -- if you've thought about it, which is NOT evident from your commentary -- 4 large shipments per year would be more than enough. Gospodin Putin would have exactly no choice but to turn the pipes back on to these nations, because his nation's economy is 100% dependent on the export of crude and natty. Losing customers on a long-term basis is not a shot on his board. Bluff and bluster are, of course, but the US (and Qatar, among others) can easily call his bluff, provided only that there is the political will to do so.
Strongly suggest you consider talking with several people who are IN the energy business, and also not confuse the entirety of the idiotic EU with the far more practical (and threatened) nations of Eastern Europe.
I don't see how that's possible. If the largest LNG tankers can transport the equivilent of 100 million cubic meters of natural gas, and Poland imported 11 billion cubic meters of natural gas, then one tanker will provide less than 1 percent of Poland's imports. I wasn't a math major but it would seem to me that it would take more than 4 tankers per year to make a dent in Poland's imports. The four countries you mentioned import over 35 billion cubic meters per year.