Extra early potatoes

I would try them against the south facing wall and bring them into the garage if the temp drops to 0. It sounds like you may not have enough light in the garage to leave them there permanently but worth an experimental bucket anyway. With the outside ones just be very careful of frost once the foliage pops up. If the foliage does get hit a bit with frost it's not the end of the world it just means your extra early spuds will no longer be extra early.