Fried Mashed Potatoes: took some of the leftover mash, squished them into patties, and pan-fried them in some of the leftover schmaltz. Results not bad. The patties need to be very thin -- I started out at thin-hamburger thickness, which was still way too thick, but squishing them down in the pan into the depth of latkes pretty much worked. Results are kind of like the potatoes from our usual vindaloo recipe, but they need a *lot* of extra flavor, either with spices mixed into the patties or a sauce on top. Simple salt and pepper really isn't enough.
Turkey Stock: nothing terribly unusual, save to note that pretty much any size carcass can be boiled down to about a quart of liquid if you give it enough time. Boiled about 3-4 more pounds of meat off the bones, then reduced. Should make fine chewy poultry stock for cooking projects.
Pan Gravy: I've never actually made this before -- our old roasting pan is flat, so the drippings tend to dry up. But this time we used Mother Brewster's old pan, which collects them nicely, so we got a couple of cups of delightfully dark sludge at the bottom, which begged to be used. So I hazarded a roux (not usually my area in the kitchen), blended in a cup or so of the by-now-turkey-jello, and stirred furiously. Results were reasonably good, but it will need a bunch of salt and spice to make it great. (I don't think of gravy as salty, but trying a completely unsalted one drives this home.) Also, need more faith that it will thicken up: the results in the middle were looking thin, so I added more flour, resulting in something that turned into library paste as it cooled. Tasty, but not the ideal texture.
Turkey Chili: tried our usual Cook's Illustrated chili recipe, substituting turkey for the beef. Used the turkey that came out of the stock, since that was already starting to fall apart nicely. Results merely okay: would have been fine if I'd just thrown it together, but wasn't worth the hour-plus of prep and two hours of simmering. Spice level was okay, but needs a *lot* more chili powder, surprisingly -- I'd say at least half again the usual recipe. (This was a particular hassle, since my spice grinder decided to die on me.) We'll see if the flavor improves after sitting: this recipe often gets better in the fridge.
The most successful leftover seems to be the plum pudding. Nuked with a dash more bourbon, it continues to make a fine dessert each night. (And of course the green bean casserole, which we killed the first day...)