Reheat a turkey without drying it out? For reasons not related to this question, I had to cook my turkeys yesterday.  My meat themometer died near the end of cooking. So I ran to the store to get one "real fast".  

Three stores later I came home to two over done birds (185 degrees).

While not totally dry, I don't want them to dry out any more while reheating them today. 

Should I slice them then heat them?  Is there a better way to reheat than another?  (ie oven vs microwave vs warming drawer vs (some other heating tool).)
You want to use a gentle heating method. For this sort of thing, I prefer steaming. It will gently bring up the heat of your food without wringing the moisture out of it. This is especially helpful if it's already cut into relatively small portions, such as slices of breast meat. Spread everything out on a single layer on the steamer basket before hand.

Warming drawer would be my second choice. Slice, add a few teaspoons of water, and cover and add to your warming drawer, set to your target temperature.