The top growth is not that important. If the rootball is intact, the plant should be fine. Is your Hellebore potted or bareroot?

As you describe the foliage, it is apparently last years growth and will soon be replaced by a new flourish.

I would plant it now. Select a location that has rich, moist, but well drained soil and receives shade during the hottest part of the day, usually noon until about 4-5PM

Keep soil moist, but not soggy, until the plant becomes well established. Usually requires about a year. After they become established, they are relatively drought tolerant.

Hellebores perform best in soil with a pH of 6.5 - 7.2

Good Luck!