Given the temperature in the hold is colder, not warmer, than normal storage, I have little concern that my bottles will be adversely affected. The contents certainly will not freeze. And since it is not for a prolonged period of time, no damage should be done. Obviously, one would not drink the wine for a while, letting it settle and restore in the cellar. My most precious bottles are the ones I carry on. [These can actually be exposed to warm temperatures, since the cabin heat can be most extreme in the compartments above our seats.]