would have more scrunch. the amount you add or not depends on your own choice.
i started with 3" knowing i would be using a 1/2" seam allowance. the blue furry pair worked well with this measurement, they were easy to get on and a bit loose over my boots. for the black low nap fur pair i only added 2 1/2 ", again knowing i would use a 1/2" seam. the black fur i had a bit of stretch (the blue fur did not stretch at all) and i wanted them a little tighter so the scrunchy folds would hold better. it is better to cut them a little too 