I just made a 3 tier cake 10, 8, 6...and used cardboard w/dowels under 2nd tier...i thought the small tier on top would be ok, since i didnt have a 6 in board. Well it's starting to sink on one side.
i know what i did wrong...but want to know if will stop collapsing or if i freeze it till tomorrow will it hold for 12 hrs??? I dont want to disassemble it now. It hasn't sunk much in 9 hours, but not sure about 16 more!

Can you put a wedge under the side that is sinking?

no, i don't think so....there is no support (board) under the 6in.....the cake is resting on the 2nd tier fondant. I cant put anything under it to lift it. What do you thinkabout the freezer?

BTW it's the 2nd tier thats collapsing, the 6 in on top of it is offf centered (on purpose). Here's a pic , doesnt look too bad. I'm afraid it will llok worse if i try to fix it.

Well...it's the next morning, I decided to not freeze it because of the decorations, although i have had success in freezing before (emergency only). I kept my home very cool and prayed. It seems as though it has not sunk any more than last night!!! Yeah! It will be warm today so I think i'll keep it real cold and transport in a cooled down car.
I'll never take a short cut again...construction is soooo important to a cake you put so much love into.

It's a very cute cake. I love purple. As you said lesson learned. So glad it worked out for you.