Welcome to the forum,
I too was looking for winter mats, I found 3 options. I looked at the Nissan mats, generic mats from canadian tire then I came across weather tech.
The generic mats are Inexpensive but likely require cutting and may or may not fit well.
The Nissan mats do say Micra on them, they also fit perfectly. But otherwise found them a bit pricey for what they are and they dont cover the foot rest and the sides. So your likely to get salt and dirt all over your carpet.
Then I found http://www.weathertech.ca/en/nissan/2016/micra/ . To be honest this is slighty more expensive then the nissan mats, but are the best at covering all the carpet against the elements.
I should receive them this week, ill give you some feedback on them if your interested.