USDA zones can be highly misleading. The interesting thing about our 10a designation is that the area of Redwood City I live in is, by and large, pretty cold! It's 10a because it never gets below 40, but most nights, even in the summer, are very chilly.
So I'm looking forward to the warmer summer nights in VA despite it being in a colder USDA zone.
The Kentucky wisteria I mentioned above is an interesting species because it refuses to leaf out until the night time temps are above 50F . And with our cold nights, that's happening just now. Literally months after my Chinese wisteria leafed out.