Freeze the food, not the lunch bag.

You can freeze food in most rigid lunch containers, but the insulated lunch bag itself should never go in the freezer. Ice crystals and cold temps mess up the insulation and can crack the lining.

Check the bottom of the container for a freezer-safe symbol or a #5 (PP) plastic recycling mark. Glass and stainless steel are fine, just leave some headroom because liquids expand when frozen. Avoid cheap deli containers, #1 plastic, or anything brittle — cold will make them crack.

The soggy problem is mostly a thawing problem. Thaw in the fridge overnight, not on the counter. For rice or pasta, undercook it slightly before freezing, and add sauce after reheating, not before. If you’re reheating in the microwave, put a damp paper towel over the food to keep moisture in. Keep lettuce, tomatoes, and crunchy things out of the freezer entirely and add them fresh on lunch day.

Freeze components separately when you can. That gives you way more control than freezing a fully assembled meal and hoping for the best.

Future You gets a real lunch instead of a sad, soggy thing.