Upon some more reflection, I believe VFR flight plans are not handled
with the ease and grace of IFR. I did file from Sacramento to Vancouver
Intl once VFR and it seemed to work. In fact, after I made an
unexpected "emergency" landing on the way in Oregon (kid in back needed
toilet) the U.S. FSS person told me he couldn't even cancel the
Canadian VFR I had filed.

-Robert