The vacuum sealer is a wonderful thing. You can also take all the meat off the carcass, make stock, and when you portion out your turkey to freeze, cover it with stock. Chances are you're going to use it in some preparation where it's in a sauce/stock/soup, anyway.

I freeze in vacuum bags and freeze some gravy in muffin tins (and then vacuum bags) and then re-assemble later.

It can be done. Nobody will say, "OMG, this is the best turkey I've ever had!" but freezing it is better than tossing it out.

If you don't feel like cooking something right now from the leftovers and you have one of those vacuum sealers, use it. If you don't, wrap it in plastic as airtight as possible.

Reheat the turkey in some gravy or a sauce: soups or stews help mask the change in texture that occurs when the turkey is cooked, frozen, thawed and recooked, and if the turkey is dry, you won't notice it as much if it's cooked in liquid. Whether they're grilled or cold, don't plan on using plain frozen-then-thawed turkey in sandwiches.

Following up on what Amanda said, you can also freeze it in stock or gravy. I have a terrific reference book, which I bought 20+ years ago (so I' m not sure it's still in print) called "Fresh From the Freezer," which recommends freezing all cooked meats in a liquid of some kind. I agree. It's essential. It's also really handy, to have that stock right there, ready to go, when you defrost the meat. ;o)

I think it freezes better if it's immersed in something like chili or stew. Have you ever had turkey Tetrazzini? Great for leftovers. Here's a recipe I ran in the New York Times a few years ago: http://nyti.ms/hfgxND