No lettuce doesn't freeze well. Once defrosted it has more a consistency of seaweed.
You can substitute romaine leaves for tortillas for wraps.
You can stuff them like cabbage.
You can cook some chop meat with Mexican seasoning, some cheese, tomato, onion, sprinkle large Doritos crumbs, at Catalina dressing; no one in our house ever tires of that.
For a sandwich, dice some avocado, shrimp and romaine.Mix in a little dill, rosemary, lemon and mustard. Get a nice loaf of sourdough or your favorite from the local supermarket bakery to serve the mix on.
Diced fish (shrimp or scallops work too), lime juice and cilantro mix. Wrap in the romaine leaves.
Dice some chicken, shredded carrots, a little fresh basil, blue cheese crumbles with a little olive oil and balsamic vinegar. (works best if you mix the chicken in the oil/vinegar) Wrap in the romaine leaves or cut hearts in half, hallow and use to serve.
Fresh mozzarella, roasted peppers, diced annie smith apples, some black forest ham or prosciutto. Oil, balsamic, oregano, a little mustard. Wrap them in the leaves or cut hearts in half, hallow server.