In response to your question about drought tolerance in the PNW, I have never seen an established planting of it here. Nor have I seen it sold locally as a landscape ornamental. Although a popular houseplant, I doubt it can survive a zone 8 winter here.

I am surprised to learn of it growing in Williamsburg zone 7 as most sources quote zone 9 as a minimum and San Marcos Growers (my go-to info source for a lot of my preferred zone pushing plant choices) states a 20F minimum temp tolerance, which is the best one can expect from a zone 8/9.

Most sources also state "medium" water requirements so not particularly drought tolerant.

It's cheap as cheap can be (especially if you know someone who has some who can give you cuttings), so give it a try and see what happens. I have it growing vigorously all over a trellis and the side of a building but I'm 9b. However, in the frigid winter of 2013-2014 it didn't die! And we got down into the teens. I agree that it does need some supplemental water but not bucketloads.

I grew it outdoors in Phoenix, drought isn't a problem but frost and poor drainage will be.

Over the years I've seen two long established local plantings of some size, one in Seattle and one in Tacoma. But the first was in a partly enclosed area and I think the second did eventually freeze back. And/or it was decided to remove it because it was just too much for the situation - this is not a small growing plant - I don't remember the specific involved details now.