Curious to how long the frozen structure can "survive". I wonder if it's a good idea to freeze one such frog and thaw it centuries later (an amphibian time-traveler!)
Not possible - the oldest ice we've found on the planet is much less than 10 million years old. Even if some area remained frozen long enough to contain an intact dinosaur, it would be buried deeply enough and under enough pressure to just be a bit more arctic oil by now.