It isn’t surprising that it hasn’t grown this season.  Woody plants often grow slowly until they have their root system established.  Of greater concern is the north-facing exposure.  Broadleaf evergreens like rhododendron often suffer from desiccation (leaves dehydrating beyond redemption) when exposed to the cold, dry, prevailing north winter wind.  A small burlap windbreak to block the winter wind would help mitigate the damage.  There are also anti-desiccant sprays available at the garden center that can be applied as well.  More on that HERE.