THIS year, I made a covered run:
...because LAST year, they were bored:
...and spent a good part of the icy snow covered days decorating my porch. They'd poke their heads up in the windows, "Can we come in? What're you watching? Is that rated G? PG?"
Once in a while we'd let them in to poke around, but within 5 minutes they'd be panting and headed back to the door "OMG its like, so freakin HOT in here, we'z haz freshest air outzide!" Somebody dropped off a few bales of hay and the chickens were delighted to spread that around, but dangit if it didn't snow a good foot on top of that so they were back to bored.
This year, I have this covered run, and plans for entertainment in there. I also have plans for a pathway to the polar opposite side of our lot, to which they can venture for another favorite space, as they've recently learned they can roost up in the branches of our giant evergreen tree, bopping happily up the ladder-like branches to infinity, and beyond....there's usually a few feet around the base of that tree which the snow does not reach. Usually.
Well that's how it happens here. I hope you get a very many, very useful ideas! I'll be watching as I need more too.