Rather than mw, can you reheat in a small pot? Or is this for the office. If so, what I'd do is reheat like I suggested and bring it with me that way. Besides the microwave doesn't warm,or thaw all that evenly, your shrimp could get rubbery.
Do you think it would be okay if I defrosted overnight in the fridge and then heated in a pot? I'm just trying to stock the freezer with lots of different kinds of soups. So far, lentil, mushroom, and chicken have worked perfectly.