Unless you want to involve yourself in some serious winter protection, look to those varieties that bloom on both old and new wood - Endless Summer, Early Sensation, Blushing Bride, the Forever and Ever series and various others. These can tolerate dying back to the ground with winter cold yet still generate colorful flowers from new growth that is produce the same season. And they run the gamut in flower colors, depending on choices and your soil conditions. I might still consider mulching heavily for some winter protection just so the shrubs develop some stature and not have to start over from the ground up each season.