Bring the white wine, salt and 8 cups water to a boil in a pot, then reduce to a low simmer. Stir in the shrimp and cook at a very low simmer until the shrimp are pink, firm and cooked through, 3 to 5 minutes. Drain and transfer the shrimp to the prepared ice water bath. Once cooled, drain and serve with Remoulade Sauce on the side.
Put the mayonnaise, sour cream, relish, seafood seasoning, tarragon, vinegar, lemon zest and juice and shallot in a large bowl and whisk to combine. Season with salt if using and cracked pepper. Serve immediately or cover and refrigerate until ready to serve.