Officially no. However if you ask at airport before you check bags yes. The main issue is that bags must fly with you on international reservations. Even though, no requirement on domestic flights, the system sees the reservation as a whole. Thus, it inhibits SDC. However if you haven't checked bags yet, am agent can easily override. Heck, as a DM I've gotten to SDC to earlier JFK-LHR flights, bags being the only issue.