I don't want to be ridiculous but I'm uncertain at what point I can freeze tamales. Do I steam them and then freeze or do I assemble and then freeze? I would like to make a large batch and freeze since they are time consuming. Also, when they come out of the freezer then what? Any help is greatly appreciated.
I would steam them, let them cool, then freeze them. If you buy them in large quantites from a vendor or from a fund raiser or something, they come already steamed.
As for prep, I would think the microwave is the best answer, as that ought to keep them nice and moist while they are cooking. Steaming them again would probably work, but might take a while. And while I haven't tried it, I suspect an oven might dry them out too much.
In response to when you should freeze your tamales; I have been making tamales with my family since I was a child. We assembly our tamales and put a dozen of them in a freezer bag. We freeze them before we cook them. We usually make them two or three weeks in advance. The morning that we cook them we set them on the kitchen counter to thaw. We place them on towels, as they thaw they drip water. We cook about 4 dozen at a time. We steam them in a big pot with a steamer at the bottom of the pot. I don't know what it is called, but it is a big disk with holes it in that fits in the bottom of the pot. We steam them for 2 - 3 hours. You know they are done when you take one out and let it set for about 5 minutes to cool. It is done when it pulls away from the corn husk easily and is firm. We have keep them in the freezer uncooked for up to a year! They usually don't last that long because we eat them! However, this year mom had some hiding in her freezer and we cooked them. They were great. To reheat after they are cooked, just steam them again for a little while.
The best way to reheat tamales either frozen or unfrozen is to wet a paper towel and wrap it around the tamale husk, making like a package. Mike for a minute if unfrozen. This way the masa stays nice and moist and never dries out. As far as freezing is concerned, I don't freeze them unsteamed because the whole process is kind of damp or wet and they could get freezer burn, I like to steam them first, thoroughly cool them and have them nice and dry, and then slip them into a Freezer Ziplock bag.
I would take the same tack as enchiladas; assemble then freeze. Use a solid bag and a heated water bath to warm filing, then steam to get tamales where you want them with respect to the shell.