The maximum size piece of fabric you can make depends on two things: 1) how many scraps you have & 2) how large your ironing surface is.
Choose what size of fabric you will make
This is when it becomes a bit of a jigsaw puzzle. You want the scraps to overlap each other a little bit but not too much.
Arrange your Scraps
If you don’t have a teflon sheet make absolutely certain that you can’t see any fusible showing in between your scraps before you iron.
Fuse your scraps into place
Start sewing on a raw edge near the edge of your piece and follow that raw edge as far as you can.
Sewing the Joins
I trim my made fabric just enough so that I have straight edges, but if you want a particular size, like a pre-cut size or strips then you can do that.
Trim your Fabric Yardage to Size