I built my first bow in my bedroom (I was in college so that explains a lot).
After that I had a small workbench in my friends basement. Built about a half dozen there.
Then I moved to northern VA and my only workspace was a 6x 10 outdoor porch. Built about 2 dozen bows, and a 8' sailing dinghy including all rigging on that porch.
My first actual shop was a 1 car garage at my apartment that shared space with my car. We had a single parking space driveway for another car. Tonuse the shop I would have to move my wife's car to he street, move my car to the driveway, roll out tools, then I could begin. I built my benches along the perimeter of the garage, and the car was parked in the middle ... it was a tight fit. But I'm betting my car was bigger than a Harley.
So how much space doesn't it take? At least 4' x 8' assuming you have a ceiling height of 8'. You're gonna have to turn the bow end for end pretty frequently. I'd wanna be able to stand back and look for tillering, so practically I think you could swing a 8' x 8' area. If it were me I'd make a simple bench at the back of the garage, and build a shave-horse that you could pull out into the workspace from under the bench. If you wanna use more power type tools, I would check out some of the small one car garage shops that have been built for woodworking because the tool storage and workspace needs are similar.
P.S. I grew up on the island, but this is why I live upstate, I can actually afford enough space.