Seems to be fairly hardy in this area. If your site too windy big leaves flopping around might get tiresome or actually be torn, I suppose, although I have not seen it damaged by wind myself. Sunset WESTERN GARDEN BOOK, although rating it for south of here only (Sunset 7 and up) says "Easy to grow under all garden conditions". A garden designer I know was going to use it for pots in a formal place way out on the fringe (Issaquah or farther) some years ago. Haven't heard how it worked out, but the point is he thought it would work for that use.

The more I look at it the less I think it is a recurvifolia. Its got the same dark color to the leaves and the flower spikes are somewhat similar, but I think the leaves in the yucca in your photo are a little too stiff and the flower spikes are a little tall (but the reason why the flower spikes in your picture is bigger than the ones Im used to might have to do with the better weather conditions). Sorry Im not 100% positive of the exact species. To me it almost seems like there are recurvifolias in the back but some other yucca in the front because the yuccas in the front seem like they have stiffer and lighter leaves than the ones in the back.

I can tell you that they do transplant well. In fact, I picked up a few large clumps someone threw into garden debris outside their house. The plants didn't even have roots at the time, and it was mid Summer (rooted without any issues). Probably better to wait for milder weather and better to take as many roots as you can, but these are really survivors. Just not sure of the wisdom moving them in this continued arctic cold. Good luck!

The recurvifolia are fairly common at your better garden centers. They should overwinter without much trouble in a zone 7 (with minor burning in bad winters). Contact a good garden center for availability.