Will my potted blueberries die if frozen?

Hi.

Noticed that the 'soil' in the pots that my blueberries are in feels frozen, although the plants look healthy - lots of little buds getting ready for next spring.

I moved them into my (brick built) shed but they still feel a bit solid.

Are they likely to die in this weather if the roots get frozen? It's not as cold as some down here on the south coast but regularly -1 or -2 these nights.

Perhaps I should dig (pickaxe?) a hole and put them in temporary like?

Our blueberries have been in large pots/containers for the past 3 years, standing outside all winter, last winter was bad for us...snow & freezing temperatures for a continious 3 weeks & they survived well, infact we had our best crop of blueberries this summer.  Just hope I can say the same after this currant snowy weather 

Thanks everyone.

Seems like there shouldn't be a problem.