I do not know what part of the Northwest Territory you are going to, but when I was in Alaska I met a man who had been to Inuvik with a pickup and trailer who lost six tires on the round trip from Dawson City to Inuvik.
I know that our tires are not as easily punctured from sharp pieces of gravel as a pickup tire, but I would check with the caravan operator about potential tire failures and available replacements or consider carrying a spare tire.
Gerald