The other S. lycioides x greggii hybrids, San Isidro, Los Lirios, and Purple Pastel are very similar to greggiis in durability. They are zone 7 plants, possibly 6, and require drainage. In Massachusetts (Connecticut River valley, zone 5b), these would be classed as temperennials, meaning they would need to be lifted, potted, and wintered over in either a cold frame or a greenhouse. There, they would probably bloom most of the summer until frost.

I wonder whether Ultra Violet is hardy in the east to zone 5b. Just because it is that hardy in Colorado doesn't mean it will be here, but it is certainly worth testing.

You might want to look at some of their other sages. Several of the types they offer have proved very hardy for me. Greggii Wild Thing has been in my garden for three years now and has always come back strong. Even after temperature fell to around 10F this month the plants continued to have lots of green leaves. Maraschino is also extremely hardy and most years does not even die to the ground. The only downside to this plant from my point of view is that it doesn't flower much until late summer. Microphylla San Carlos Festival has also been here for some 8 years and although it generally dies to the ground it comes back with a passion. None of these are rated to zone 5b but I wonder. After all, the minimum temperatures for a particular zone aren't reached every winter and even small yards have micro zones that are warmer.