Is your soil frozen? Can you dig down to see how dry it might be below the surface? There is no transpiration going on now so the shrubs will need far less water than they would in season but the root zone should not be allowed to dry out. The flip side of this is that moisture tends to stay in the soil in winter (there being no - or very little - evaporation going on), so watering needs for landscape plants tends to be drastically reduced.

Check as best you can for the need to before watering unnecessarily.

Has your snow melted yet? If not, just plop a few shovelfuls of snow around the plants - as the snow slowly melts and the ground begins to unfreeze, the snow will gently water the ground. I use this trick with stored potted plants, and it works great :0)

Melting snow will work like a drip irrigation. This is the best way to water in a winter :-))

I use shovelfuls of snow to protect some of my plants from the darn rabbits.

If your soil is frozen you shouldn't be watering. He hit 38 degrees last week and the ground was definitely still frozen.