In a medium bowl mix together crushed pretzels, melted margarine, and 1 tablespoon sugar. Press mixture firmly into bottom of a 9x13 inch baking pan. Bake in preheated oven for 8 to 10 minutes, until lightly browned. Cool completely.
In a medium mixing bowl, beat together softened cream cheese and 1 cup sugar until smooth and fluffy. Fold in whipped topping and spread mixture evenly onto cooled crust.
Place gelatin in a medium heat-proof bowl and pour in boiling water. Stir gently until gelatin is completely dissolved. Add frozen strawberries and continue to stir until mixture begins to thicken. Chill until semi-firm but still pourable. Pour gelatin mixture over cream cheese layer. Chill at least 2 hours before serving.