Its worth a try. Even if you were to keep the plants in light and in moist (not wet) soil all winter, the temp drop itself will cause your bulbs to have at least a very short dormancy, even in the garage. If you plant your bulbs right now into a pot, they probably will go dormant just from the "stress" of being repotted this late, but it should get them through the winter and they should bloom at their normal time for your zone. Keep the soil in the pot from freezing solid. Depending on how cold your garage, you could cover the whole pot with a frost blanket if you know it will get really cold. That's what I am doing with these 6 big pots which I have just planted. I 'll throw a blanket over the whole thing if frost is predicted. I'm hoping that black pots will absorb heat during the day, and keep the soil a bit warmer at night. The disadvantage of large pots is the difficulty of moving them. I use a refrigerator mover. The advantage of large pots is keeping a more constant soil moisture just from having a larger soil volume. It does cut down on watering. In my own situation (zone 9A), potting my bulbs on Nov 15th, caused all the leaves to go yellow and die back in 5 days. I may not have any top growth at all until Feb. That's OK, as long as the bulbs don't rot this winter. That's dependent on how much rain we have, and how wet the soil stays.
