Definitely do not trim it. All you can do is wait and see how it gets on as the weather warms up. But I am not too sanguine. Rosemary is evergreen in climates where it survives the winter. I've never had it go brown.

Turning brown is not a good sign. If it is dying you should know very soon. If it really starts to brown quickly and you can find some green branches personally I would take a few cutting but not until then and try to get what green branches strip back the leaves and place into root tone then soil, and see if you can at least save a few as new starters. They usually start to die from the center out so if this is what is happening you need to make those cuts quickly.

I overwinter a few rosemary plants inside my house and usually about half of them turn brown and die. Rosemary is not easy to grow in New England. I am guessing that the snow smothered your plant and killed it.

Thank you for the advice. It does look like it's going fast. I was able to salvage a few shoots which I have . Not sure if bringing them inside from cold weather to indoor temps is going to hurt the process. Right now they are in the garage near a window in high humidity environment but probably 40 to 50 degrees F and not very bright.