You can prepare lasagna ahead of time and store it in the fridge or freezer depending on how long you want to store it. It can be frozen cooked or uncooked for 2-3 months. This is also perfect if you have leftovers. If you are freezing the lasagna uncooked, leave lasagna noodles raw. If cooking after freezing, defrost in the fridge overnight or on the counter for up to four hours before baking. Then bake as normal.