Combine the limeade base. In a large pitcher, add the thawed limeade concentrate. Then, pour in the vodka and 40 ounces of water, or the amount specified on your limeade concentrate package, to make sure the perfect balance of flavors. Stir well to combine.
Add the grenadine. Slowly pour the grenadine along the side of the pitcher, allowing it to settle slightly below the limeade. Use a long spoon to gently stir, just enough to mix the flavors slightly while keeping the beautiful gradient effect intact.
Prepare the garnishes. Using a sharp knife, cut enough fresh limes into rounds so that you have a few slices for each serving. Adjust the number of slices based on your personal preference for garnishing.
Serve. Fill each serving glass halfway with ice cubes. Place a couple of lime slices over the ice in each glass. Slowly pour the cherry limeade over the ice, allowing the layers to remain slightly separated. Finally, add some maraschino cherries to each glass for a sweet finish. Before serving, gently stir each drink to blend the flavors just a bit while keeping the layers visually distinct.