how can i winter Yew shrubs in pots in -20 below weather?

Question

Yews are already in winter outfitter’s fabric bags.

Answer 1

They are hardy to zone 4 but if they are in pots and you aren't going to plant them before winter you can wrap the pot in burlap or bubblewrap. Or, you can sink the whole pot in the ground and bring it up again in spring.

Here are more ideas:
https://www.gardeningknowhow.com/special/containers/overwintering-container-plants.htm