Lack of success overwintering rosemary here so I can't say for certain but I would expect it to have stayed mostly green-ish.

Even though thyme and sage do look different and maybe a bit ragged in the winter, they don't look dead. Here is sage from my garden in a snow-ladened february. Still looks like sage after 3-4 months of cold and snow - albeit a bit purple looking for a regular old gray-green sage.

But wait until things start to warm and grow in your location. Who knows? It may still be alive. Give it a chance. What have you got to loose?

FataMorgana

I'm in zone 7 too. I have two large rosemary plants that have been overwintered for several winters now. They do get a bit unhealthy looking, but they always spring back. However, they never look dead. They just aren't as green. I don't do a thing to them... no mulch, no additional watering, no fertilizer. If your rosemary looks dead (brown), perhaps the burlap kept your rosemary from getting enough sunlight. If it looks dull green, it's probably still okay. Bend, and break, a stem. If it is green inside, you're in luck!

Here is a link that might be useful: Planting Herbs Indoors

I have an old 4-5 ft. rosemary 'tree' that I fear has succumbed to our recent rare minus 9 degree weather this winter! Son has prostrate rosemary trailing over a wall that seems to have been 'bitten' also; only hope they both may come up from the ground again. The fig & pomegranates I have though- if frozen- will come back up x the roots but will be a couple years before any fruit again! Was 37 below just outside the City (Albuquerque). Was a real unusual winter for us here & drought conditions already in effect! Hope your rosemary has survived despite soe dry branches!

Probably there are different kinds of rosemary. But the ones around here(ATL, GA) are evergreens. Our winter lows rarely goes down to single digits. Mid teens is normal lows. At this temps, rosemary stay alive and well, only the leaves turn a little brownish. The cities also plant them in the landscape, along with lavenders and some varieties of sage.

I have tried overwintering my rosemary too. But I have tried it in the house beings I'm in Iowa. My Rosemary lasted until just a few days ago. So I will try again this next winter. I recently had a farmer tell me how to get it to winter over in the house. That was when I get another one to plant it in a pot and then leave it in the house. The only help I can give has already been said. If it looks dead it probably is.