Ok so I made an extra lasagna to freeze. It was loaf pan sized and I got it out today. I wasn't sure how long to bake it but it turned out great. Sure it wasn't as good as it was fresh, but totally worth it! Much better than the Stouffers ones. When I made it, I left it uncooked (the noodles and meat were cooked) covered it in plastic wrap then in foil.
So, for a completely frozen loaf pan sized lasagna:
-Preheat oven to 350 -Remove plastic wrap, replace foil. Place lasagna on a cookie sheet -Bake covered for 90 minutes. Remove foil, bake for 15 minutes.