They should be able to be planted as long as the ground isn't frozen solid - a bit of frost won't hurt them as they should be dormant now. If you have to wait, I'd pot them up, put them somewhere really cool, don't leave them as they are. One thing that often happens with fruit plants sold in these stores is that they get too warm and start to wake up before it's the right time.
Bear in mind that your blueberry will need acidic soil (ericaceous) and may do better in a pot anyway so that you can give it the right soil. And watering only with rainwater helps too.