I have several large hanging baskets of boston ferns which live outside during the summer. I tried overwintering them in a spare room in our house which has minimal light (one small window). I watered them about once a week. They made it, but looked pretty rough by the following spring. Took a long time for them to recover and fill out to look nice. Last year, before first frost, I cut them back to about 8-10", and stored them under our house. I had added florescent lights to test overwintering several of our plants that otherwise would have to come indoors. We have a brick home and the temps under our house never go below 55-60 degrees. I watered once a week or less during winter. I started watering more frequently around February and they filled back out nicely by the time I put them out this spring. This is just my experience, but I think they do best with good light even in winter. I'm not sure they will make it with little to no light.

Hope this helps.

Some ferns (like the common Boston Fern) really are "ever growing" plants. In other words they don't have a dormant or down time. That means they need light constantly. I overwinter mine in my unheated garage (which has windows in the garage door). By spring they will have lost about 1/2 their foliage and look pretty ratty. However after dividing them and giving them new potting soil, they will bounce back in a month or two. Although I wouldn't swear to it, I think your Shamrock plants are actually bulbs that do have a dormant phase, so you couldn't compare their needs to an evergreen plant.