Overwintering a baby rosemary

I have an 'baby' rosemary plant in a 5" pot; Alcalde Cold Hardy variety. Over the past 5-6 yrs I have lost my established rosemary plants due to freeze. They were not hardy varieties.
Should I put this in a bigger pot and keep tucked under patio next to house for the winter or even bring it into garage? Water how often?
We have had several nights this past week in the 20's.

Thank you.

I have lost many rosemary plants, I now have two big survivors, both 'Arp', on slopes in yucky clay. I never tried your variety. I do think spring planting is the way to go, these marginally hardy things seem to really like to be established by winter.
This one is in such a tiny pot you might do best to put it on your sunniest windowsill for the winter. Do you have a south window? If not, I would not repot it but might sink it into a bucket of rocks or gravel (with hole in bottom so it will drain). This might protect it from temperature fluctuations as the pot is so small. If it gets below about 25 again maybe bring it in the garage that week. I think it would die from lack of light in the garage if you try to keep it there all winter. I would not repot, rosemary hates being soggy and if you repot when it can't grow new roots it will likely stay soggy. Thus, my rock bucket idea.

Explain to me what you mean 'into a bucket of rocks/gravel'. Place the whole 5" pot into the bucket? I have an upstairs bathroom w/ south window. this bathroom does not have a furnace vent in it. maybe a good place for rosemary to spend the winter? water occasionally?

The window sounds perfect. I would water occasionally, letting the top get dry before adding more water.
The rock bucket was just an idea i had. I have found that little pots around here can have problems in the winter that I think are from frequent freeze-thaw cycles. the little black plastic pots seem to really pick up what little heat is in the sun, then freeze solid at night even when my big pottery planters have not frozen. One year I sank some plants in 5" pots in an existing planter, and they survived much better. I had the top of the soil in the pot level with the top of the soil in the planter.
so I thought maybe just getting a bucket or big gallon plant pot, (with holes in the bottom) and sinking the 5" rosemary pot into it, might hold heat and cold somewhat, and buffer the freeze thaw cycles while under the porch. But I like your cold south window better anyway.

thank you mlmlakestevens! during the winter this bathroom doubles as my wine cellar. so now it is a wine cellar/green house.