Q.Will Bare Hemlock Branches Get New Growth
I’m thinking of taking out 2 of 3 hemlock trees that are overgrown, crowding the house, neighbor’s yard, and each other. The remaining hemlock tree will have then have a side exposed that is currently quite bare (lack of sunlight). Will it fill out again by growing new needles on those branches, or should I just cut it down as well?

Certified GKH Gardening Expert
If the branches are dead, they won't grow new leaves, but you can prune 50 percent of a hemlock and it will recover. Here is how to prune:
https://www.gardeningknowhow.com/ornamental/trees/hemlock/pruning-hemlock-trees.htm