Yes, now is a good time. The way you handled it last year seemed to work fine, so just keep the tarp handy! The only thing the freeze would do is kill off any tender fronds, but more would grow back even if it did.

I live outside of Atlanta and have ferns in my wooded damp backyard. I no longer cover them to protect the new growth during the late freezes that we get. They grow right back. I plant ferns anytime during the year - it doesn't seem to matter.
My biggest challange is finding their favorite spots in the yard. I can plant 3 of the same ferns in different areas and one may thrive while the others eventually die out. Some varieties just don't like our soil/weather and they die out in a couple of seasons. The best luck I've had with non-native ferns is Autumn Fern. It must love our soil and weather. No matter where I plant them they grow very well they stay stately and green all winter.
Good luck on your fern garden