They say to store bulbs in a cool, dry place that doesn't freeze. The garage will be fine for now, but if it's an attached garage, once freezing temps come you will need to insulate them so they won't freeze. I have had luck with those styrofoam coolers (or any other cooler).

That said, I have stored bulbs in my home at room temperature, planted them in January, and most of them turned out fine. Some of the smaller, special bulbs dried out (frits come to mind) but the daffs and tulips came up great.

If your garage is not attached to the house, the planters will also need to be put in a cooler or under a pile of blankets as well, to protect them from hard freezes.