Always go with square footage for future proofing.
People never realize that 200-400sqft reduction in house footprint is actually almost DOUBLE because of the additional room mostly or totally comes from main floor area. This also results in basement!
I would look into a Tandem attached. 22' wide, with a deep high tandem bay. Do a lift there. If it's possible do a 24' wide, but with 22' its a good trade off for space and allowing the home to be all it can be.
You can do a lot with elevation, go maximum height with 5-6 steps up to entrance and this will allow a 11-12' garage height. Ensure maximum storage around the perimeter of the double portion so nothing is on the floor, and go lift in the tandem side with plenty of height.
"The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents... some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new Dark Age."
-H.P. Lovecraft