We're in Northern Vermont, so probably fairly comparable weather.
Wrap the indoor run area (The run that has a roof and is enclosed in hardware cloth) in heavy plastic.
Put tarps over two sides of the fence in the outdoor run area. This gives them a place outside where the wind is kept to a minimum.
Buy some hay and put it somewhere dry. I'll put this down over the snow.
Buy a big container of meal worms. Nice cold weather treat.
Put away the water dispensers I use in warmer weather. Set out the heated dog water bowl, which is where they get water in the winter. We have it on a cold sensitive plug so the bowl only warms when it's below 32. We don't keep water in the hen house (where we close them in at night) during the winter. Keeps the humidity down.
Put down an extra deep layer of bedding in the hen house.
Make sure I have extra grit and dirt for when the ground is frozen.
Stand outside the hen house and contemplate drilling more holes for ventilation. Every darn year...
That's it, I think, for prep.
We never heat our coop. We made sure to get cold weather breeds and the girls go outside all year round. We make sure they get lots of good food, including warm oatmeal and meal worms. We keep the bedding deep and make sure to keep it especially clean in the winter to keep the moisture down.
I'd be afraid of fire, and I'd worry the chickens weren't acclimatized to outdoor temps. What if your heater failed?
On "warmer" winter days I'll open some of the hen house windows and get some fresh air through.