Figure out if you need to "open a US subsidiary" later.
And besides, "opening a US subsidiary" sounds a whole lot better to the visa-issuing folks and the funding folks and to the folks in whichever US region you might want to move to than does a business in its bootstrap stages.
There is success beyond SV.
There is funding beyond SV.
Ship it.
Figure out if you need to "open a US subsidiary" later.
And besides, "opening a US subsidiary" sounds a whole lot better to the visa-issuing folks and the funding folks and to the folks in whichever US region you might want to move to than does a business in its bootstrap stages.