I live in exactly that kind of pre-war streetcar suburb and yes, I've heard suburbanites complain that the houses in these neighborhoods are too small and narrow and lack attached garages. So yes, even the moderate walkability created by streetcar suburbs is still requires a shift to noticeably smaller homes for many North Americans acclimatized to sprawl.
You can have sizeable homes even in walkable neighbourhoods. Look at any suburb constructed pre-WW2:
* https://www.google.com/maps/place/150+Geoffrey+St,+Toronto,+...
* https://www.google.com/maps/place/150+Westminster+Ave,+Toron...
* https://en.wikipedia.org/wiki/Streetcar_suburb
You still have a (back)yard and can have a garage attached to a laneway. Just up the street there are more modestly sized houses (3 bedrooms usually):
* https://www.google.com/maps/place/50+Geoffrey+St,+Toronto,+O...