Upsizing a window - how to make the hole in the wall align?

Update: I made it work, posting here in case someone has the same problem.

The issue was the Model Cutout, found in the Warehouse. It was still just making a hole in the wall that fit the old window. Luckily I had used a different, bigger window for reference, so I opened it in S4S, exported it's model cutout, and then imported that into my own project. That added the reference window's data to my window. When I clicked "edit items" in the "data" tab of the Model Cutout in the Warehouse, I saw all my old edges (the first 8) and all the new, imported edges (the last 8). I deleted the old ones and kept the new ones.

At first I tried just using "edit items" to change the values of my windows edges, but that didn't work.

After that I also had to open the mesh in blender and lower it, because the reference window was low to the ground, where my window was high up. After doing that, everything fit!