Adding the Borders
Okay, this is where things can deviate if you don't want to do it the way I did. At this point I could have cast off and then added the borders like you do with a ten stitch blanket with mitred corners. I didn't feel like learning how to do a mitred corner so I opted to have four live edges (and bought more cables because I didn't want to transfer to scrap yarn). So as you work each side of the border, you'll also still be picking up a few stitches as you work each side.
Are you up for an icord bind off?
Because my live edges are in teal, I needed to do one row in the charcoal (or the colour you are using as your MC) and then do the icord bind off on the return row. This gives you a clean icord edging in your MC. However, doing it this way meant that I had to fudge my corners together.
So if you are working off all live edges, and have enough connectors to create a giant cable, then I would put all edges onto the one cable. If you do this, when you get to the corners, you need to do a kfb for the two stitches on each side of the corner. This will mean your icord will curve nicely as you bind off, though it may feel a bit awkward as you knit the row of that corner. You stay on the right side of your work to do this.
However, if you'd rather cast off and work the icord on the finished blanket, you need to work from the wrong side. And I found this tutorial that shows you how to do it.