For lasagna, I can get 4 dinners out of one recipe! For now anyway :) A loaf pan is the perfect size for one dinner for us, but use whatever you have! You could even buy disposible loaf pans, freeze them and cook right in the pans and throw them away. I make one pan for us to eat that night (no foil) and line 3 pans with foil. Flatten the foil as much as you can. If there are any bumps, pieces bunched up, or overlapping, it will get frozen and stuck in with the lasagna! So flatten out any bunchy spots. The foil is solely to for easy removal from the pan, not to cook in. I had done that once in the past, and got tiny pieces of foil mixed in with my lasagna when I cut it.
Note: Studies have shown in books that I've read that aluminum can be bad for the brain. I still use it in cooking, but I try to limit my use. Mostly I use it to cover a pan to keep it from drying out in the oven, and I try not to let it touch the food. But for something like this, I'm not heating it in the oven. So I don't fret too much. If you're concerned, do some research and come to your own conclusion... because I am not a scientist :)
Make the layers in the pans, and your lined pans will look like this. Pop in the freezer over night. Pull the frozen lasagnas out and let them sit on the counter for 5 or 10 minutes. This will allow them to loosen from the pan without ripping the foil. Pop the lasagnas out of the pan (they should slide right out). The foil will be slightly frozen to the dish, so gently pull the foil off. If you flattened it when you lined the pan, the foil should peel right off. Every once in a while, a little piece of foil will get stuck in a crack of the pasta or layers, it's pretty easy to chip those out. This batch was perfect! Peeled off without a hitch!
I can fit 2 loaf pan lasagnas in a gallon bag. When I'm ready to cook it, I pull one out and put it into a loaf pan. Perfect fit! You can cook from frozen or thaw in the fridge in the loaf pan. 350 degrees for 45-60 minutes. I don't typically cook it from frozen, so I'm not sure about how much longer to cook it. But I'd add at least 30-45 minutes.