It depends on the size of pot. They will survive in a pot but if your weather is below freezing most of winter I would burry pot in ground partially and maybe cover with mulch of some sort.

Don't worry about its first-year size. They don't tend to grow much from their first season. In fact, I think they do most of growth in early spring after the first year. The fall die-back is usual also, especially with younger ones. They are not evergreen.

Overall, Ostrich ferns are pretty hardy and they multiply well. Each fern could produce one or more off-spring by rhizomes each season. Plant your little fern in ground before frost and next year you could start getting additional ones. They will also multiply in a pot if given enough space.
I LOVE ostrich ferns and use them almost like ground cover and accents all around the garden.

Here is a link that might be useful: Ostrich fern is an award winner in my garden