in your locaton both would be too cold.. have you tried to overwnter the brugs n the garage before... wthout heat there.. the slab of the floor will have it too cold... much less the air leaking in around the garage door .. on the sides as well as aganst the floor... look at it durng the night.. with a light on in the garage... stand outside with the door closed... if you can see light around it.. that cold will seep in... and the garage floor is likely uninsulated.. and will in no time at all.. be the same temperature as the ground outside... whitch in your area is frozen solid for monts on end during the winter... so the pots sitting on the floor will be below the minimum you need to keep them alive... if you hope to keep them in the garge.. I'd get them up off the floor.. and put in a heater... and then watch them as the temperatures fall.. they can never get below 32* F.. in higher zones...overwintered outside below 32 the tops will die off.. and the ground temperatres being warmer a few inchess below the frozen ground will keep the roots alive... you likely freeze to below 16" there... take cuttings of everything and raise them in the house.. what ever you do
