Yes, you can plant!! If the plant is fully hardy for your zone and the soil is workable - not frozen (unlikely in z7) or overly saturated - you can continue to plant as late as you like.

I once installed a full perennial garden the week before Christmas.....didn't lose a thing!

I sure hope not, because I have 10 Twist of Lime abelias sitting in pots in my front yard, waiting for a new fence to be installed before I can plant them. :) As gardengal said, they will be fine!

Depends on the kind of shrub, and how cold it gets after they are planted - this late in the year there is likely to be little establishment of them occurring until next spring, starting with spring bud break.

Soil temperatures can remain warm well after a light frost.....you need consistently cold temps both day and night for it to lower much. And as long as soils are reasonably warm you will still get some root establishment.

I plant all winter long in my slightly milder climate.

In zone 7 you can plant until the ground freezes hard, especially plants in containers. This is a great time of year to plant trees and shrubs.

Timing of root growth of cold climate adapted woody plants is regulated by hormones produced by overwintering stem buds. Once setting of these buds has finished prompting a significant elongation of existing, intact roots in fall the winter mode is basically one of hibernation. This late in the year some kinds may have set bud two months ago.

Production of new roots from cut root ends occurs when winter stem buds open in spring.

The traditional commercial cycle for finished stock that is to be sold bare rooted aligns with this biological schedule. With plants ready to be dispersed dug in November, placed in cold storage for the winter and then sent out the following year, for late winter planting.

Such material has no feeder roots at time of planting, with new roots bursting out of the old, often cut back main roots as soon as spring bud break has occurred.

^^ None of that alters the fact that hardy woody plants can continue to be planted as long as the soil is not frozen. And that is highly unlikely in a zone 7 and especially this early in the season. There may not be much root elongation or establishment going on over the colder winter months but the plants will be primed and ready to take off as soon as the temps warm in early spring.