These 3 ferns are several years old in pots and outside in Iowa in the summer. I can prune them back that far or not as much but have to over winter in a dark basement not going below 55 degrees.
They will prefer to stay, actively, growing. They can handle a dormancy, but they are easier to maintain as a houseplant. Here is an article that will help:
https://www.gardeningknowhow.com/houseplants/boston-fern/boston-fern-care.htm
It could be a fungal infection. Remove all the browning stems and cut back on watering. When you do water, water deeply so the water runs out the drainage holes.
https://www.gardeningknowhow.com/houseplants/boston-fern/boston-fern-care.htm
Not sure what to do if my fern is salvageable or not
Brown and dry fronds on your Boston fern may be due to low humidity, inadequate watering (either too much or too little), insufficient light, temperature stress, or nutrient deficiency, particularly nitrogen. Ensure consistent moisture, provide adequate light, maintain suitable temperatures, and consider fertilizing to address potential issues.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/test-soil-for-pests-and-diseases.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/making-sure-soil-drains-well.htm