I put them in 12" pots and up. 16" and up works better, the 12" pots needed to be watered too often in 90+ temps. It reached 100 for a few days and they would be starting to wilt when I got home from work!

I had 1 of 2 come back in the garden bed with no protection, but next year I will fill a garbage bag with leaves and put it on top, then put a tarp over the leaf bags and should get all back. I dont know if you'll have to go through all that though. The pine straw will probably work just fine for you. The one in the pot I put in the the "basement" it gets down to 40 in the coldest of the year, but it died when my table full of Japanese Maple (semi-bonsai) collapsed on it and broke the pot it was in.

A little afternoon/evening shade would probably be best for you, but they could probably take full sun.

Other advise...watch for hummingbirds! They love the Black and Blue!

I've had one in a 16" pot for several years. It's probably overdue to be repotted because it's surely rootbound by now, but I never seem to get to it. In my hot dry climate it does suffer a bit in the summer. It wilts a bit without water every day when temps get above 100, but otherwise it puts on quite a good show of flowers and foliage.

Winters have never been a problem. 15-20 is the typical low here, with 10-12 this last winter and absolutely no protection for the pot. Do be aware that they can be extremely slow to sprout in the spring. I put one in the pot recycling area one spring only to have b&b wake up and shout 'I'm not dead yet!'

As for repotting, they are one of the few salvia to form tubers, so they are extremely easy to transplant and multiply.

I am in the central Sierra Nevada 3,600' elevation in zone 7ish. My winter lows normally are just into the teens, though I have had 0. *f . Winter snow has occured as early as Nov. 5 and often we see the most snow in Feb and March. A few years ago we had an accumulation of 42" of snow in March!
My B&B's are for the most part in pots, never with any special covering for Winter. If the stems are left on the plant for Wintering over, it may offer some insulation, but I doubt it makes much difference at all. The pots are ranging in size from 3 gallon to 5 gallon black plastic nursery pots, and a couple of "fancy" decorative plastic pots. Although I prefer clay pots, freezing temps make these a poor choice for over-wintering.
All of my B&B's have come back each year with little care provided for their needs beyond the occasional side dressing of compost, re-potting with new potting mix, and applications of seaweed extract to keep them happy and healthy. I do protect the B&B's from too much hot afternoon sun, as they really perform best that way. The ones that are in afternoon sun are in clusters of pots that shade the black plastic pots and keep the roots from being baked in these pots.
The one I planted in the ground last year was planted in our unforgiving clay in only slightly amended soil. As of today it is approx. 4' x 4' and covered in flower wands.(which I have found are a beautiful addition to flower arrangements, by the way!)
B&B is by far one of my favorite Salvias for not only being the Hummingbird magnet it's known for, but those amazing true-blue flowers and bright green foliage.
Enjoy!

Thanks, everybody, good discussion! I am feeling much more optimistic about being successful at this, esp. overwintering. I want the hummingbirds so it's good to hear that it will bring them. Appreciate your help!