Growing Lavender in the Northeast

We live in Zone 5.  As anyone who grows in the north is aware, some winters can stretch the definition of where a zone starts and a zone ends.  Some of our winters can bury you in cold and snow for months on end and other winters it seems to come all at once in the last month of winter.  The major decision we have to make each year is what varieties to plant.  We have planted lavenders rated for our zone yet they failed in the first winter.  We have had other varieties that seem to almost thrive in our winters.  Now I can pretty much look at a variety and see if it will survive our winters.  I look for varieties that are tight compact plants that are very robust in foliage.  The foliage is almost succulent in the way the leaves grow, compared to some varieties that are more airy in nature.  This is hard to describe I will have to take some pictures to show the differences.  Some varieties that I love are Folgate, Buena Vista, and Grosso (to name a few).  They meet my criteria and green up quickly in the Spring. They are definitely winter hardy.  Different farms in our same growing region may have different results.  They may be in a more sheltered area and subsequently have more success with certain varieties than we have had.  They may live in a micro climate which defies local planting zone rules - lucky for them.  Here I contend with strong winds most of the year, yet I have the luxury of a lime rich soil left by glacial deposits dragged to my fields millions of years ago.  Advice?  Find varieties from a reputable grower that are grown true to type and test which ones will work on your land.  We have had extreme good fortune with some of the varieties and the quantities we purchased.  We wanted to get established quickly and bought varieties by the 100's not in batches of 20 or so which might have been more reasonable.  Luckily after our first major losses we met up with our reliable source,  Stonegate Lavender in West Linn Oregon.  Sarah there is a wealth of knowledge and helped us select varieties that worked for others in our region and suggested some others to test that she thought might work for us.  With those suggestions, along with our constant vigilance and adjustment to our growing surroundings, our fields have begun to take shape.  Bit by bit the farm is coming to life.