When did armies stop establishing winter quarters to rest through winter?

Up until fairly modern times it was unusual or even unthinkable that an army would operate during the winter months in Europe, Asia and America, but it seem sometime during the World Wars era this practice largely stopped in favor of armies operating year round despite the winter clearly still being a major obstacle, especially in WW2 and the Korean War.

Is it just a question of technology getting better or is there something else to it?