Size isn?t everything
From your post, I see you?re in central IL, not quite the cold climate of western Wi, but I?d imagine the cold days are plentiful this time of year. I?ve been building on and off for 6 years, on most of the time, off as in a few trips overseas as an expat to help pay for this hobby. In the 6 years of the build, it was getting time to move from a garage into a hangar, and luck and life circumstances allowed me to purchase a hangar this past year. While in winters past I would transition into anything I could do inside, such as deburring any part Van?s sent (first winter?s inside project in the basement), or building FlyLED boards (2 winters ago), my garage wasn?t very well insulated so heating was ineffective at best. Now that I have a heated hangar, the work doesn?t have to slow down even if the temperatures dip below zero (yes we?ve had some of those already this year), and it seems, at least to me, that I?m knocking things off the list at a fevered pace. So size aside, make sure your shop is a comfortable place to work.
If you are close to an airport (I?m a 5 minute drive), I?d consider that too. More than once I?ve borrowed tools/ or grabbed supplies from others right at the airport while waiting for an ACS order to come in. Also, when I?m at the hangar, I tend to work with more focus than I did when at the house, as there?s less distractions than at home.
As for size, my hangar is 32x42x12 and the RV-8 shares space with an N3 pup ultralight with plenty of room. It has a loft/apartment above and in back, but I mostly use that for storing parts. I think that is big enough, but take that all with a grain of salt, since it may not be someday when I finish this plane and build a RV-18 or whatever the plane of my fancy is at that time. Also keep in mind what kind of person you are, as for me, I?m not interested in boats, tractors, campers, (well, I am, but I realize that having a bunch of half-assed hobbies is more work than it?s worth) and all of that other stuff that seems to end up in hangars throughout the land, if you are, take that into account when you size it. Even draw it in CAD, with birds eye view drawings of everything you want in there and see how it nests.