The capacity of the LNG terminal in Klaipeda is 23,9 TWh per year, Lithuania alone consumed around 24 TWh per year in before this year. While consumption is probably going to be lower this years due to the massive spike in price there still is no way it can provide enough gas for Lithuania, Latvia, Estonia and Finland.
>Only pipeline connection from Russia to the Baltics is this pipeline
No. Latvia has a direct connection to Russia at Korneti which is where the majority of natural gas consumed in the Baltic states is imported at. So even if Finland buys any gas from the terminal in Lithuania that only means that more Russian gas is consumed in the rest of the Baltics (so effectively pretty to close to being the same as just buying it directly from Russia)
https://www.helen.fi/en/news/2022/helen-to-break-away-from-r... with similar moves by the other gas buyers in Finland.
Only pipeline connection from Russia to the Baltics is this pipeline (Balticconnector) as it connects to the Finnish gas grid that has its own pipeline to Russia and through the national grids and the pipeline between Lithuania and Poland that I guess allows access to the Russian pipeline in Poland.
So no clue where Estonia would get that Russian gas from.