I planted mine in rows next to the south side of the house to try to provide a little shade in those blistering hot summer months. Planted about 5 feet apart, centenial (5, only 4 up so far) along one section separated from the rest as they seem to spread and tangle alot underground. Cascade (5, all 5 are up)along the sunniest wall because I have heard that they are prolific on the foliage front and one single sterling (no sign yet but it's only been a week, the guy who gave me the rhyzomes only had 1 sterling and it was only 3 years old so there wasn't really much pruning to do) on the west side of the house in front of the bedroom window so it will help us sleep when we have the window open.
we have had a couple light frosts since they broke ground but no one seems to mind. I would guess that right next to the house they are probably kept a little warmer than they would be in the middle of the yard.
I couple tricks for early spring emerging plants in colder climates:
Plant on a north facing slope if you have one. This will discourage early growth and decrease the chance that they will emerge/bud(for trees) before the last killing frost has happened. You might also be able to build up a bit of a mound of earth (or earth and logs: google hugelkulture) and plant on the north side of that. I don't know if that would work or not though.
Place large dark colored rocks near the base of your planting. If you are getting warm sunny weather the rocks will heat up a little during the day and help buffer night time temp swings a bit. Also think about prevailing winds and try to figure out a way to block them a bit to further moderate night time temps.
And as several others have mentioned you can mulch with straw, cover with pots or even mulch with slightly under finished compost.