Custom two-column panels layout

The current problem I'm having with the 2-column layout is that the top of each region are both very important, and the bottom of the regions are less so.

I would like to try a 2-column panels layout that actually has three regions. The left column is broken into two regions: left-upper and left-lower. The right region is a just "right".

Something like this:

+------------+------------+
| left-upper | right      |
+------------+            +
| left-lower |            |
+------------+------------+

But when it went narrow, the "right" region would slip between the two left regions, like so:

+------------+
| left-upper |
+------------+
| right      |
+------------+
| left-lower |
+------------+

Another, similar layout could be four regions like so:
Wide and normal:

+------------+------------+
| left-upper | right-upper|
+------------+------------+
| left-lower | right-lower|
+------------+------------+

narrow:

+------------+
| left-upper |
+------------+
| right-upper|
+------------+
| left-lower |
+------------+
| right-lower|
+------------+

It would need to be able to slide up, though, so it could look like this, depending on the content:

+------------+------------+
| left-upper | right-upper|
|            +------------+
|            | right-lower|
+------------+            |
| left-lower |------------+
+------------+

but when "narrow" still be able to slide together:
narrow:

+------------+
| left-upper |
|            |
|            |
+------------+
| right-upper|
+------------+
| left-lower |
+------------+
| right-lower|
|            |
+------------+

The problem with using the multi-layer layout is that if you put stuff below the full-width region, it doesn't slide up.

So, what do you think? Do you think this is possible?