For the maple bacon: Preheat the oven to 325 degrees F. Line a baking sheet with tin foil.
Stir together the maple syrup and brown sugar in a small bowl. Arrange the bacon in a single layer on the prepared baking sheet, leaving a slight gap between each slice. With a pastry brush, coat the bacon with the maple syrup mixture.
Bake until the bacon is crispy and the sugar is caramelized, about 25 minutes. Cool slightly, then carefully loosen the bacon from the foil while still warm. Set aside.
For the spicy Bloody Mary: In a pitcher, stir together the tomato juice, clam juice, lemon juice, Worcestershire, garlic powder, onion powder, paprika and 2 teaspoons of the celery salt to combine. Season with black pepper and hot sauce. Once you are happy with the flavor of your Bloody Mary base, add the vodka. Chill until ready to use.
When ready to serve, put the remaining 1/4 cup celery salt on a shallow dish larger than the rim of your highball glasses. One at a time, dip the rim of 6 highball glasses into water, then immediately dip into the celery salt to form a rim. Fill the glasses to the top with ice and evenly distribute the Bloody Mary mixture among them. Make 6 skewers each with a cherry tomato, pepperoncini and slice of cucumber. Garnish the drinks with a skewer and a slice of the maple bacon.