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

Here in south eastern Ontario the winters last from late November till early
April.  Of course every year is different.  We don't usually experience any
real long periods of bitter cold (less then -18c, 0 f).  Once the days warm
up above 10c/50f  I usually remove the tar paper.  I only use tar paper and
nothing else to wrap the hives.  I use 1/4" screen along the entrance, no
reducer,  the top of my hives have an old super on them with 4 screened
holes and an inner cover with a large screened opening for ventilation.

Kent Stienburg