We've had 2 cold winters now in my region in the south west and temps went down to -5 some nights - which is probably not as cold as you or others get !!!
However, my point was that all my varieties of Verbena have survived .... the ground cover types aswell as the mid range and taller ones ..... all lived through them.

depends on which species. V bonariensis has mostly come through this winter, whilst the bedding ones are only annuals and wont survive the frosts anyway.

Yes. I wasn't talking about annuals Snapdragon, were 'you' ?

I've just seen that you've asked this question twice.
You now have answers in both areas.