> A question I would like to post to the experience northern beekeepers
> out there is
> -what factors do you consider before removing the hive winter wrap?

Take them off when you can no longer do your necessary tasks with them on.
May?

Personally, I may leave some of ours on all summer since I have new design
that allows working and supering with the wraps on the hives.

In Alberta, many northern beekeepers wrap their package bees with (at least)
black plastic until mid-May.

allen