Well no telling how much snow their will be so i cant really say yes to this idea id say no just because devs could use the time to make something more versatile usage ( yes i know people can use snow mobiles for more then just snow but rather just have a 4 wheeler)
Snowmobiles would be pretty cool, but like Lt Snake said, we don't know if snow is even a possibility. Seasons change, so this would be a very specific timeframe to use the vehicle. If it were added, however, I think it would have to be more effective than the four wheelers people drive around.
If there is any snowy parts on the map, or for special events at winter, if you are going to do something like that, you could implement a snow mobile that makes it easier to get around these environment. There could also be a different type of vehicle (like a snow mobile) that could get around on regular land.
Maybe but I know where I live if it's a cool climate that a lot of people in rural areas have them, I would have the wheels more rare.
We could also have them and use it like the Alaska shows such as bush people or mountain men.