We're getting married outdoors at a State Park on June 23. We're ordering a cake with Italian buttercream frosting and raspberry preserves between the layers. It would costs $90 to have the cake delivered, so friends offered to pick it up on the way to our wedding. The cake will be unrefrigerated for at least 4, possibly 5 hours. The cake decorator suggested using dry ice in a container beneath the cake to keep it cool once it's at the site. But she was not specific in how to do this. Does anyone have any ideas? Thanks!