Rugs, Carpets and Carpeting - Carpet runner on winding stairs

Good day,
We have an older home with wood stairs that turn on the top 3 stairs. When we purchased the house they were wall to wall carpet. We took it out and redid the stairs. But now our dog doesn't like to go up or down them w/out carpet on them. So we were going to put a runner on them until we sell and then just take it off. My question is how do you install the runner on the winding parts? If you cut the carpet on an angle it will be wider than the next part. Or perhaps I am looking too much into this. Please help, want to get this done before the weekend so my pup can have fun running up and down.
Thanks so much!

Do each of the angled steps individually and break it where the tread and riser meet. If the widths vary on the steps in question, cut the carpet of each one individually to accommodate the difference, however looks best to you.

That would be an easy thing to do, but of course my Fiance purchased a runner with a pattern and border, so i just can't cut it and make it look good. I think I may be out of luck on this one....thanks though!