Let's make our countries small again!
For starters, Finland: Soviet Union decides to demand Lapland from Finland in 1944, let's say from Rovaniemi upwards. As it's economically inconsequential and far away it's almost nothing compared to territorial disasters of losing Karelia and Porkkala.
Second possibility: President Kekkonen manages to trade Lapland north of 67 latitude (little north of the Arctic Circle and Rovaniemi) for a piece of Karelian Isthmus, including Viipuri, in 1968.