I couldn't really say without experimenting. For short term usage, though, what Comsic says makes perfect sense.
For blends I planned to then store for years, I'd have two concerns (which might prove non-issues, but they would still worry me a little). First, freezing can break the cell integrity in plants. This might not have a material impact on smoking tobacco, since the leaf is dried so significantly, but I couldn't say for sure. Second, depending on the length and severity of the freezing, it's possible that some microorganisms that effect fermentation (or other processes) could be killed, leading to a different (but not necessarily worse) aging process.
All of that said, I wouldn't really worry about it. I worry more when I have wine deliveries, and even then I worried more about the heat than the cold.