Sounds like a poor ideal to me. Dogwoods tend to be a bit more on the picky side, and that does not sound like a great environment. However, what would do we there depends upon the soil beneath, sun exposure, climate, salt, drainage, etc.

Arktrees

Kousa dogwoods, of which 'Satomi' is a cultivar, develop quite a broad, spreading canopy with age. In fact, it is not at all uncommon to see well-established trees much broader than they are tall. And since like all flowering dogwoods they do not respond well to much pruning, probably not a good selection for that specific area.

Yep: there's white Kousa in Seattle (USDA 8) 50' tall or wide. Perhaps 'Miss Satomi' is a little smaller than usual but should still be expected to grow beyond 15' within a reasonable period of time. However, there have been a few forms with dwarf growth habits in commerce, maybe you can find one of those. One with pink bracts was called 'Dwarf Pink', do not know current availability.