Winter sunshine (when it happens) is helpful to warm the colony and allow opportunities for cleansing flights outside the hive over the course of cold winter months. I use leftover political "correx" signs extending well past the hive top cover to create a drier area around the hive.
It sounds like the shed is geographically inappropriate.
Bees like their morning sun...
I use a Fred Dunn "visor" on my hives to keep rain off the entrance.
I have a shed attached to my house and have just one colony so it would be easy to move the hive just inside the shed door. This would keep it out of the rain and snow and give it some of the house heat.
Or, leave it the field where it gets morning sun.
Any suggestions?
Thanks.