Puree strawberries, lemon juice, and 3 cups sugar in a food processor. Press through a fine sieve into a bowl, discarding pulp. You should have 6 cups puree.
Prepare an ice bath; set aside. In a medium heatproof bowl set over a pan of simmering water, dissolve gelatin in 3 tablespoons cold water. Add 1/2 cup of the strawberry puree; return mixture to bowl with remaining strawberry puree.
Set bowl in ice bath until mixture is chilled and slightly thickened, about 20 minutes, stirring frequently. In a separate bowl, whip 2 cups cream to stiff peaks, and fold into strawberry mixture.
Cut parchment paper into 16 strips, each 2 3/4 by 10 inches. Tape each strip around a 3-ounce ramekin so it extends above the rim by about 2 inches. Place ramekins on a rimmed baking sheet; fill each with about 1/2 cup strawberry mixture. Freeze until set, about 3 hours.
Remove from freezer 20 minutes before serving; remove parchment collars. Whip remaining cup cream with 2 tablespoons sugar.
Serve souffles with whipped cream.
Makes enough for 16.