It may not be too late to change the garage openings, talk to the contractor about it..
Money spent now won't feel bad compared every time you look at the wasted space.
Move the air compressor outside, closed in storage.
I think I am actually ok with it now. The wife can keep all her stuff to the small side of the garage and I can put a 4 post in the center of the bigger area and have room to work. If I put it on casters I can move it to the edge and park 4 cars if needed.