I wouldn't put it inside, it takes too much work. Planting it permanently now would be great, or if you don't want to do that, just submerge the pot into the ground for the winter, and move it to wherever you want it in the spring.

It should fare just fine outside in your Illinois winter; these are very hardy plants, even as babies.

-Ben

Plant it out and it should be fine. It will likely die down to the rhizome for the winter, but should come back just fine. I would give it a good mulch as a safeguard. In a few years you'll have more fern shoots than you know what to do with!

As someone who has plenty of ostrich ferns in zone 4, northern Minnesota, with new babies cropping up continuously - plant it or sink the pot outdoors now.

This is the time of year they're starting to yellow and get ready to die back for the season, so expect that with yours. They're perfectly hardy down to -50 degrees Fahrenheit which is probably somewhere in, I don't know, zone 2? And the fastest way to do it in is to treat it as a houseplant and kill it with kindness.

Great! That takes the stress off. Thank you all for your help!!!