James Bay Canada

Hi all,
I need some advice concerning necessary gear to take on a work related trip to James Bay Canada. We will be going in February for approximately two weeks. The average low and high T are -13F and 12F without windchill. For the majority of the time we will be working outside or in tents with small space heaters powered by generators. When I am not working, I do enjoy winter backpacking but have not had time in years due to school and work. Thus, I would like to obtain some gear that can be used in less extreme winter conditions (specifically the NC mountain area) after the trip. I have come across some nice North Face down gear, but am afraid that it will be too bulky when packpacking. I have also run across a company, Arc'Teryx who I do not know much about. So basically, what I need are suggestions concerning a nice pair of boots, a jacket and some bibs or other pant type clothing. I appreciate any help.
Thanks, Kevin