I find it occassionally in lakes/ponds in Massachusetts, so I am guessing it overwinters up there. If this is the case, it will be fine in Virginia year round.
I've had some in the past and then they died on me. Now I have some more and they seem to be lasting this time around. I don't think I'm doing anything different either.
If it dies it is relatively cheap to replace. A couple of bucks for a decent size bunch. I have had it survive and die in the winter. I think it has a better chance of survival if it is sunk to the bottom of the pond in winter. I usually bring in a few strands for my turtle tank. It gets eaten but grows fast enough to have a litttle in the spring. I just let it float at the surface so my golfisk can use it to spawn.