Basil is a tender annual. That means 1.) it only lasts for 1 growing season and 2.) that it cannot survive a zone 6 winter. It is just dead sticks, sorry!

FataMorgana

It might have some seeds around it. My basil sent seeds everywhere last year.

Other than some a couple of holy basil seedlings last year which was after an unusually mild winter, I've never had any basil self-seed. I suspect our cold and long winters are not friendly to basil seed.

FataMorgana

Lime basil and lemon basil are the only ones that reseed for me. And they didn't do that after we had a hard freeze that lasted several days. We usually have very few days that are freezing or lower, and that doesn't kill them.

But you can take cuttings and root them and bring them indoors for the winter. I like the African Blue Basil, and that's the only way it is grown, it doesn't make fertile seeds.

Sweet and Thai Basil seed very well here but you have to let it go to seed so I always save one plant that I let produce all the seeds I need plus some to share. The seeds I save I find are so much viable than any I have bought. Your Oregano and sage should do fine but your Rosemary will need protection in your area. If nothing else can save your Rosemary take cuttings for starts indoors for the winter months in your area to set out come warm weather.