In a medium bowl, toss cranberries with 1 tablespoon lime juice. Drain out lime juice, then toss with 2 tablespoons sugar. Pour onto a baking sheet to dry.
Combine remaining sugar with salt on a shallow plate and mix to combine. Using the lime wedge, wet rim of each glass, then dip in sugar salt mixture.
Combine cranberry juice, tequila, triple sec, remaining ½ cup lime juice, and ice in a large blender, working in batches if necessary. Blend until smooth.
Pour into prepared glasses and garnish with a sprig of mint and a couple sugared cranberries.
