I agree with Cindy. Turning the pot on its side is the secret to avoid crown rot. The rot is caused by heaving, adding standing water in the pot because there is ice in the pot that blocks drainage.
I learned about this from potting hundreds of hostas that overwinter in my zone 5, almost zone 4. I wait until Thanksgiving Day to tip them over because they will be dormant.
With daylilies, I certainly would ad mulch. Do not be in a hurry to stand them up, but do remove the mulch before the pot becomes too hot and causes rot.
