Our house is from the 1960s and only has a one car garage. It has five bikes in it (which get ridden) and a Concept II rowing machine (ERG). It also has a de facto pantry for all our dry goods. We have a shelf of school and art supplies. At the other end is my workbench and most of my tools. I also keep my mountaineering gear in there because the one out-building we have does have some humidity (since it is unheated).
But to people who say, "whoa, I'd hate to see what the rest of the house looks like!" I would point out that by moving all that stuff to the garage, the actual house is much, much less cluttered.
p.s. I have two driveways and as such, use them for parking. I always assumed that is what they were for. I don't "care" about my cars, so it doesn't bother me if they are out in the elements. There is no crime to speak of so they won't get stolen. I left the car door wide open overnight by mistake last week and the following morning everything of value was still in the console.