An estimated 190 million people in the U.S. were subjected to the polar vortex's icy blast.Farmers worried about their crops.Diane Cordeau of Kai-Kai Farm in Indiantown, Fla., about 90 miles north of Miami, had to pick her squash and tomatoes Monday to beat the freeze but said her leafy vegetables, such as kale, will be sweeter and tastier because of the cold.I am the queen of lettuce around here,