Upper Levels Hey smart people, Combine C&C with Midwest??

I currently have a 2x4 C&C and have 5 or 6 more grids unused and could buy more if need be. I have a good amount of Coroplast too.

I have a Midwest Habitat Plus (the one with lid and divider) that I've used in the past but always used the lid panels and divider panel to expand it.

I currently use the cage panels to create floor time area:

I also have a brand new Midwest Cage (this one with no lid or divider, just the liner and cage grids. (I bought it for someone who didn't end up needing it and I only paid $25 so it was a steal!).

I want to create a cage with a large upstairs and downstairs. I really can't go bigger than the space I'm using now for the 2x4.

I'm thinking I can lose the ottomans it sits on now and use the grids to build an elevated 2x4 and use the extra Coroplast I have with the cage grids from the Midwest cages to build a large downstairs that slides under the elevated upstairs. I just don't know how to use my C&C grids to build a stable upstairs that stands free since I can't attach it to the Midwest lower level that will exist.

Make sense? Any input on how to do this or better ideas using what I have, please advise!