Well, that is quite an imaginative fantasy. Nice period flavor, but didn't some pan-continental railroads already get built?

Eric, it's labeled Rhododendren x 'Northern Lights'. It's one of the few that are hardy this far north. I don't grow Rhododendrons that have evergreen foliage, because winter winds and sun would damage the leaves. Jean, you must have a much larger variety of Azaleas available to grow in your milder climate. Julie

GREAT!! That's a good one,...er, two!! Kt

An "appendage" garage is very commonly added to a main side-load garage. Usually site constraints are the governing issue. Using @User 's pic for illustration, the important components are making sure you have the space in the corner where the BLUE rectangle is. That allows the front to swing out when backing out of the inside corner garage all the way to street. That area can also serve as a daily backhouse entrance. The ORANGE rectangle inside is an efficient way for storage and to connect the garages rather than through the house. As an additional crutch if the site allows, a turn-around area of the driveway is good for 3-point turns so you can drive forward out of the driveway (shown in RED arrows but came out pretty sloppy, sorry). Shown with a bball court for my fun. There are many iterations that can happen in terms of layout, which garage is where (maybe 4 + 1 appendage, 3 + 2 detached with breezeway, 2+2+1 tandem, etc), whether it's a separated in-law suite, whatever. You will find little love here on Houzz for ANY garages, but if you need advice when more information is known post and some useful comments may actually trickle through.