I would definately do overnight shipping. If your going to be shipping several bags, go to an LFS and see if you can get an extra styro box or 2 from them with the cardboard box that goes around them. If your just shipping 1 bag, you can use a small box and fill packing peanuts in around the bag. This time of year, I would use heating packs. You can get them at academy, something like 2 for a buck. For a styro box, wrap 2 heating packs in a sheet of newspaper, and tape it to the inside of the styro lid. I usually fill the bags 1/2 water, 1/2 air, depending on what I'm shipping. Whenever I ship branching SPS, I attach the frag to a small piece of styro so that the frag will float upside down in the bag. This helps protect it from breaking. Make sure to get it to the shippers in time so they can deliver next day. HTH