Wedding Cake help please

[Snuff62]

Can anyone help me find a plastic cake storage box that is at least 40cm in diameter or 40 cm square (internal measurements), and at least 18-20cm high?
We have to pick up a wedding cake on 24th Dec for the wedding on 28th Dec, and need something to store it in. Cardboard boxes are no good for this particular cake.
I'm beginning to think I probably need a "large plastic storage box" and turn it upside down!

Thanks everyone!

Just bumping for you @Snuff62

I would go with your upside down plastic storage box. That, essentially, is what a Tupperware cake container is, writ large.

A piece of cardboard cut to size covered with baking paper stuck on the other side will give you a flat base if necessary.