Hmmm.... I will share what I did, but I want it referred to as "the annabakescakes outdoor reception insulation method" when sharing I used a card board box, (18"x18"x24")the same size as the base the cake sat on, and tall enough to not squish the top of the cake and closed one end with box tape, and cut the flaps off the other side, so it was open ended. Then I got some sheets of ice pack bubbles, you get them on amazon for $10 a sheet, and waterproof tape. before freezing the bubbles, i added tape flaps to them and punched some holes in them with my hole punch, making sure not to pierce the bubble! And then I got some of those little brass jobbies that look like a thumbtack, with two legs that you open wide to hold papers together, (they are built into some large envelops) and attached the ice packs all over the OUTSIDE of the box. Freeze for a couple days. It also helps if you don't tape the top together until you take it out, if you don't have the freezer space.
I froze the cake for an hour and half (I was running a half hour late) and set the cake in the cake transport box I have (like the one from the CalJava you tube video ) and took my ice box out of the freezer and wrapped it in 5 layers of heavy duty foil. I did this as neatly as possible so it wouldn't look crazy and rigged up.
After I set up the cake at the venue, I slid my aluminum foil ice box over it. It looked so stupid! But it sat there for 3 hours in 85° F weather and looked great when they pulled it off after the guests arrived but before the bride and groom got there. The cake was still chilly, and they served it an hour later, in perfect condition.
I didn't take pictures because I was winging it, and charged the bride $50 for the box, and the venue threw it away. It was worth $50 in materials, and $30 in labor, lol. It would be something to charge for or get a deposit for and have returned. It worked great!
Anna, this is brilliant. I am filing it away for future reference. I wish I had known about it a couple of weeks ago. I had a wedding planner who insisted on picking up a cake because her client didn't want to pay my delivery fee (looong story). I could have offered her a version your box for 1/3 of what the delivery would have cost.
Thanks! I actually attached the icepacks to the box first then froze, but you could easily do it the other way around. I forget why I did it the way I did, but I remember there WAS a reason... I debated about it, but I have the freezer space, so I went ahead with attaching then freezing. I am a loon...