Q.Have beautiful purple barberry
This year we had a lot of consistent rain and it did damage to many of the branches – those we have tried to cut off. When it starts getting cold should we leave the bushes alone or cut them back for winter – which is the best way of having them come up healthy next year.

Certified GKH Gardening Expert
Here's an article with tips on how to care for it:
https://www.gardeningknowhow.com/ornamental/shrubs/barberry/barberry-shrub-care-tips.htm
The best time for pruning is after the bush has flowered in the spring, but cutting away dead and damaged branches should be done now.