Been there, done that, though the first time was not by design. A number of years ago my family and I were leaving the day before Thanksgiving to spend the Holiday at a second home we have in Florida. Because of severe weather all flights were cancelled and nothing was going to open up for at least 24 hours. We returned home that evening with no plans for Thanksgiving dinner.
Thanksgiving morning I thought about the issue and went went to the grocery thinking they might have defrosted birds available. No such luck so I picked up a frozen one. I knew it was going to take longer, but not by how much. I figured we could wing it since weren't having guests anyway. From a food safety point of view, I figured by the time it was fully thawed during the cooking process, it would zip through that hypothetical 40F-140F corridor pretty quick and it did. As I recall, at 350F it was done in 4-5 hours. The best part of the fluke experiment was that it was one of the most succulent and moist whole turkeys I've ever cooked (I normally part out a whole bird).
On a few spur of the moment occasions, I've repeated the process with the same results. I've also done it on large meats such as frozen pork butts or briskets. Never an issue.
If you search some credible sites you'll find info regarding the safety of this process. One I found is below.
Edited by dls1 - 8/8/13 at 1:59pm