It's hard to top Frenchy's cooking method. I dropped an email off to HeaterMeals about their meals in the winter and got a rather helpful reply.

Keep in mind that some have posted here that they hate HeaterMeals. I eat them without any complaints. Try before you have to use them. :-)

The HeaterMeal infoperson says the heating element will not cook a frozen meal. It is expected that the meals will be heated to 100 degrees above the starting temperature, but it can't thaw, then cook the meal. They say the meals are carried by snowmobilers and such, but the meals are carried inside the parka so they don't freeze.

Storage in a hot trunk lowers the shelf life of the meal. Entrees can be frozen without problems, but the HeaterMeal Plus packs have beverages and snacks and should not be frozen.

Meals are cooked, then sealed, so the heater only heats it up. They can be eaten without heating, although I shudder to think of it. (They heat from pouring saltwater on some magnesium -- both included in the package. No flame or other equipment needed.)

Louise and I have them in our grab and stay kit, and we always take a few to Burning Man for when it's too windy to cook and we need a meal. We may have other useful information for winter rations at
http://www.cieux.com/bm/quickMeals.html
which has lists of foods which require little or no preparation.