I cozy my re-hydrated meals for 5-10 minutes. I use a cheap 50 cent plastic lid sealed bowl. I thought about using Reflectix for cozy material, but I found a lighter cheaper alternative.
There are two jobs Reflectix accomplishes. The bubbles inhibit conduction of heat, and the foil reflects radiant heat back into the source.
I always carry a wool knit hat with me camping whether the expected temperature calls for it or not. It's an insignificantly lightweight piece of clothing. Even in the summer, I find it useful in the cool of the morning before sunrise, when I'm just warming up for the day. It's just one of those items I carry with me to ensure I'm warm in my bag if the bag doesn't seem to be doing its job, or if I get wet. Most heat loss is through the head, so it's indispensable in all seasons as far as I'm concerned.
I find that my sealed bowl fits perfectly into it and wraps easily around it. There is far more insulating power in the thickness of the cap than in the bubbles of the Reflectix. This slows heat loss in the bowl, and water temperature stays closer to 100 C during the re-hydration process. Sometimes it takes 20-25 minutes to adequately re-hydrate shrimp or the beans of my chili , so the wool cap is particularly helpful to keep temperature high in those instances.
To handle the radiant energy, I found that a large bag of Cheetos with the inner foil lining is excellent. I just slide the hat wrapped bowl into the bag and fold it over. Putting the entire assembly under my sleeping bag doesn't seem to hurt either.
The only added weight to my pack is the miniscule weight of the foil bag, which I just fold up and store in my bowl when not in use.
Although a tasy bag of Cheetos
costs around $4-5, the bag itself is free--a much cheaper alternative to buying a $14 roll of Reflectix or an $8.00 roll of windshield sun-shade (the cheap dollar store sunscreen is not bubble wrap). In addition, you don't need to buy a $7 roll of aluminum tape to hold it all together.Hope you all find that useful. Just something I found practical for my set up.
..You're frugal and constantly seeking cheaper alternatives to ridiculously expensive items.I think you'll find we make a habit of that;especially RR and I.. 
Atta boy!
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