No need to despair.
They will survive. Third photo- worst plants, but they had only recently been potted up some weeks ago, however even these will be o.k.
Tough as nails.
The pictures show actual conditions, snow would have been welcomed by the plants, but perhaps not by humans, as it would have provided a nice duvet .
Far more likely to kill is the penetrating strong EAST wind, hence the temp shelter of some plastic sheets to give a little respite.