So with the falcon wing doors you couldn't open up passenger seats in your standard garage. I'd suspect people who could afford this wouldn't have a standard garage anyways though.
This is one of those things where if what you said is true, then the engineers would be brain-dead morons. I suspect it's more likely that it does work in most standard garages, than Tesla's engineers have never thought to try it in a standard garage.
Musk actually demoes it opening in a low-height garage. It has two hinges for the door that lets it open at less height.
A standard garage seems to have quite a bit over two meters in height, which should be enough to open the doors. They also have sensors and adapt both hinges to obstacles next to and above the car.
Let's say you take your AWD SUV up to your cottage in the mountains, or to a ski resort, and you've got 6" of snow on top of your car. What happens when you open the doors?
You clear the snow off before opening the back doors. You should be clearing it off before you drive anyway so it's not much of a difference.
He showed it in a standard garage setup, but I would fear my garage door opener would be in the way... Hopefully the ultrasonic sensors would see the garage door opener and not hit it.