Keep them warmer!! Keep them growing all winter if you can. Brugs do not need to go dormant at all, they are tropical plants. They bloom year 'round in Hawaii where they don't get as low temps as we do. Maybe try moving them to the back of the garage and use a grow light with a timer on them if there isn't a window? Or, ideally -
If you have a sunny window in the house, you could keep at least one or two growing full blast indoors. I'd still cut them back halfway or so to keep your house from becoming a jungle, but if it comes time to move them in, and they are in bloom you could take the plants indoors, enjoy the blooms for a week then when they're finished, cut the plant back (but leave some leaves!) Keep up the water and fert but probably at a lower rate than outdoors. Then when you set them outside in the spring, once the nights are warm (above 50deg. F at least) up the fert againn, and they will spring right into bloom, and you could get 3 or 4 bloom cycles over the summer.
Start the cuttings for more plants, to grow or give away, too. They root really easily. I just put the cuttings all together in water, in a bright area, keep them warm and they have enough roots to pot in a week or two. If the cuttings are made above the first Y, they will form a shrubby plant rather than a tall tree, and will bloom much sooner, too. I've had cuttings put on flowers while they are still in the water.
They need to be warm. That's the 'bottom line'.