I've been driving dully's for many years now and do not have problems with parking spaces. But, I do have to plan it out a little, and make compromises. Unlike the family beetle VolksWagon, you can't park everywhere. Airport parking garages are one example. But parking on the ground is no problem.
My dully has never prevented me from going anywhere. But, I do have be a bit creative when parking, and willing to walk a little.
However, if you have a truck camper on the back of your truck, regardless dully or not, you'll never be parking in a high-rise parking garage anyway.
Edit:
Snow: I live in Central Indiana. We get snow. Not 6 feet at one time, but we still get it. Pop the truck into 4x4 and snow is no problem. Actually, because we live in the country, our car is too low to the ground to go through some of the snow we get sometimes. We use the truck almost exclusive when it snows because the drifts and such get so deep, the car would never make it. The truck is our life life in the winter! ... yes... all 6 tires and 4x4.