Honey is usually greater than 80% sugar solution when produced by the bees. It is stored in the hive, sometimes for years if they did not need it for food - the brood nest rarely extends to the outermost frames - and it was not removed by the beekeeper.
Rarely are the outer frames of stores consumed by the bees (especially by those of new beeks, as they often feed the bees with sugar syrup (or fondant) in hugely excessive amounts). Stored honey can easily granulate (probably due to human intervention of cropping cycles). While the cells are capped and moisture is kept out, the honey will not ferment.
Now, for how long does the OP wish to store this honeycomb? Is it capped or not? Opened cells will ferment at normal room temperature - that is why bees cap them! Reducing the temperature to -5 Celsius is likely sufficient to prevent yeast growth, so -18C, in a freezer, is more than adequate for preservation.
RAB